Note that it doesn't have external bays, so you won't be able to put an internal optical drive in it.

Dell engineers. I vouch for them, they are very good at building computers, especially servers.

Dell laptops are also top notch IMHO, at least the ones I've used (which admittedly are business laptops, which probably partly explains why they are of such high quality and leave a warm fuzzy feeling in your stomach, like swallowing a whole cat or even a bear cub alive). I really love how many options they have in their UEFI setup, hence giving the user lots of freedom and control. Also Linux runs great on Dell laptops.

Acer, HP and Lenovo are much worse at least in the UEFI options department.

Like they say in the Dell TV ad: Choose Dell, or go to hell!

Use https://ca.pcpartpicker.com to help you choose some compatible parts. It's not 100% accurate, especially when it comes to CPU cooler heights and case widths, but it'll give you a good idea.

Fans do come with the case, but unless you spent a premium ($100+ CAD), most of the included fans will be 3-pin fans with no speed control. That means it's always running at 100% speed when you've got your PC on.

This is not ideal for some, so oftentimes they'll order 4-pin PWM fans too. In this case, these will vary in speeds based on temperature control. If you can't get the 3 pack of Thermalright TL-C12C X3 from Amazon.ca, I'd recommend Arctic P12 PWM fans for $10-15/ea. There's also a 5 pack out there for $50-60 CAD. I don't know what your case is, but I think 3x120mm intake + 1x 120mm exhaust is pretty common that will get you a lot of cooling.

As for picking mobos, I'd consider if you'll be gaming and/or running at high power draws. If you are for long periods of time, you should get one with higher quality VRMs ($150+) that ensures you have steady power draw and lifespan for your motherboard. If you're a casual gamer, you can get by with a budget board just fine ($100-120 CAD).

After that, you should consider other miscellaneous features depending on your applications. For example, USB type C for front port or better audio codec if you plan to produce music. What mobos were you thinking of getting?

You could build your PC within a chair 🪑 🛋 🛸 you are sitting on. It might get warm, good for winter. Or straight within your desk cupboard 🗄 All it takes is a fan hole 🕳 and a GPU->🥵🌬 <-Case Fan to take the hot air out. And some tools 🛠 And some stickers! Stickers are a must. And some Christmas LED lights 🎄 arranged in 🌌 nice patterns. And You. You are a must : ) &#127857, and all parts are sorted. Lumberjack approved ; )

No DVD. It does have two 3.5" HDD bays.

OK that isn't a big deal I guess. I can forego the DVD drive.

With that said, micro ATX cases are cheaper and fit better for micro ATX boards.
I wonder if micro TX cases have room for drives and DVD drives

Obviously fewer, and also fewer fan slots. But really look at the maximum video card and CPU cooler size for those.
I really wouldn't put top-tier components in a micro case or on a micro board.

If you need to buy an extra exhaust fan you can pick that last when you know where, if and how big, both width and thickness. They are not all 120x25mm even if that is the most common size. Maybe you will not need one due to a liquid cooling radiator pushing air out or there is only room for a 20mm thick one.

Yeah, it's a budget gamer build. 4090 is the most expensive, not 4080 super, but the only reason I want CPU and GPU to be top notch is so I don't need to upgrade it 5-10 years later.

So from that perspective, it is most frugal move for cheap gamers.
Saving money on the long term.

A 4080 Super now, on its own, seems to be more than any computer I ever bought cost, or thereabouts if you find a really good deal.
And if you intend to keep the computer for a long time you may get more bang for your buck if you look lower and do upgrade later, because even a 4080 Super will get outdated in a few years, but it'll keep drawing 300W and you'd have already spent an arm and a leg on it.

Apologies for the late reply re (what to look for when case shopping)

I see there has since been a lot of helpful replies which is awesome.

For myself, I always just consider what ports & how much space I will need & go from there. My current case is a Fractal Design Meshify C which covers everything I need (a few SSD mounting spots & room for a couple of 3.5" HDD)

As for you wanting to use a DVD drive, you could always buy an external USB one if you haven't already

It also depends on what types of games you play and what monitor you use. If you're aiming for a 4k display with the latest, cutting edge, high fidelity single player games, then yes, it'll age over just a few years. However, if you're overspeccing for a 1440p monitor and say, playing games that are a bit older or have lower GPU demands like multiplayer games, you can likely get 5-10 years out of it, plus it'll be a cake walk for the card in the earlier years so the power draw will be lower.

Keeping components long term can also have reliability challenges. I only have a mid-range GPU but after a few years, it developed problems with overheating and fan noise. Granted, it was probably at 100% load or close when playing games in those first few years. So I'm forced to run it at a lower power limit now. Even then, it still seems to get hot. Unsure of the root cause. Could be low quality thermal paste.

Next time, if I can ever afford a GPU with these prices, I may get a higher spec card and power limit it from the start. I reason the card's cooling would be designed for a higher thermal output so by limiting the output, I might extend its life. There's a few articles and videos out there, sorry no time to hunt for them, that show the performance vs power consumption is not linear. You can reduce power consumption to 80% or 70%, sometimes even lower, depending on the game, whilst retaining most of the performance.

If you are not space constrained then keep the ATX case, which will accomodate micro ATX mainboards as well.
If you are building the PC by yourself, something you may want to take into consideration is convenience.

ATX cases are much spacier to work in than micro ATX ones, so, it will make it easier to replace/fix something down the line when filled with hardware, means better air flow as well for active and passive-cooled components.

A good modern case can be full or partly tool-less, basically in the assembling process you won't need tools or rather just some basic ones.

A 20-25cm long phillips screwdriver with magnetic head or, even better, interchangeable magnetic heads is required.

Optional ones are a pair of tweezers like the ones used in surgery

Optional as well but very, very useful: I've found great relief and anger-reducing using a klemmer surgical plier, especially for seating those little case connectors/SATA/USB to the motherboard, you can lock the grip and use them as extensions of you hands. I have big hands and operating in those cramped spaces is inconvenient and unnerving.

It usually doesn't work out this way. If you're buying the very best you are paying a hefty premium. Meaning your GPU might be 30% faster but 100% more expensive (numbers made up). That slight performance edge hardly ever makes or breaks a game 5-10 years in the future.

IMHO you are better off with going for best value. Especially when it comes to components like the GPU that can be easily switched later on. If you do have some extra money and want to build a long lasting system I'd put in into CPU/Mainboard/RAM as those can't be upgraded individually most of the time (a new CPU usually needs a new board which then needs new RAM). But that's just my personal recommendation