Looks like a very nice selection in the main, especially for that price - couldn't dream of getting something with those specs for that price here in South Africa.
Let me see if I can add my $0.2:
I don't know much about Intel i-chip overclocking yet, as I still use my Yorkfield quadro, or even if you plan on OC'ing, but, if you do, its just good practise to make sure that with the RAM you purchase that its of a type where you can at least attempt to keep the ratios between your chips' Bclk/QPI/Memory Speed/ Uncore Frequency - but from the look of it being 1800MHz you shouldn't have too many problems with raising/lowering it if you decide to OC, as ratios don't "have" to be maintained. But 6GB of triple-channel RAM should serve you exceedingly well.
Like others have said, check the brand of your HDDs. I may be brand-blinded, however I have had bad experience in the past with certain drives: I'm talking about you Toshiba and Maxtor. Can't say I know much about Samsung drives, have not tested any myself. I've generally used Seagate and Western Digitals drives, more or less without problems. To be honest, you can't really go wrong with either, unfortunately failture rates are a part of the risk involved in mechanical drives (well, in all manufactured components really, but especially prevalent in mechanical HDDs).
The current generation of Western Digital drives, as well as the previous generation, do not have any "known" issues so apart from the built-in probability of drive failure, you should theoretically get the manufacturer's lifespan (MTBF): between 30-40 years on a mechanical driver or 120-170 years o a SSD, or so they claim :P - one advantage to Western Digital though is their 5 year warranty.
If however the drives are Seagate, just a quick caveat. The previous generation of Seagate drives - firmware version: 7200.11 - have problems. If your drives happen to be of this line, upgrade your firmware from Seagates site as soon as you get them (usually done by writing the firmware upgrade onto an optical disk and booting from that disk). If however the drives are version 7200.12 you don't have anything to worry about.
Let's see... RAID configs: judging from the overall size (1TB) I'm going to assume this is going to be a RAID 0 configuration. Generally I would advise against a RAID 0 setup, although some fanatics would have my head for that, but, here's why. The gains from a RAID 0 config are minimal, and in my opinion do not fully account for the risk involved in the setup. In a RAID 0 setup data is striped across both drives, meaning, if one drive fails the data is pretty much lost forever (as data is constantly written, "striped", across both drives), and if you take into account the 5% HDD failure rate inherent in every HDD (and if my stats101 is still accurate, you would end up with a 10% chance for your data to be lost in a RAID 0 config with new HDDs: P1(Drive Failure)=5% & P2(DF)=5%, and since P1 & P2 are not exclusive, P(of RAID 0 failure)=P1+P2=10%
The 10%, right off the bat failure rate with new HDDs (as HDD failures, in the main, occur at inital activation or within the first 36 days), is simply not worth the average 0.2-0.8ms seek-time gains (maximum RAID 0 seek-time gain I have tested has been around 1.5s) you will get over simply having the drives run individually. So, if I were you, I wouldn't run the drives in RAID 0, but thats only my humble opinion :) However, if you plan on using them for storage and want redundancy then I would recomend a RAID 1 config - but that is definately not for performance. If you want best performance and reliability, stick to individual drive configuration without RAID, at least ifyou are only going to be using 2 drives for now.
As to future-proofing: only thing I can add here is just check if the motherboard has SATAIII - although mechanical drives are not likely to hit that barrier anytime soon with their current builds - they (rpm<10000 drivers) are now just reaching SATA I thresholds. So, I guess, SATAIII is a moot issue. Other than that, PCI-E versions don't look to change anytime too soon - all seems fine to me.
Afraid I can't comment much on liquid cooling; I've always used air and have managed to OC chips from 2.4Ghz to 3.6Ghz in 34 degree ambient temperature (it's hot in Africa :P ) without, under full load, the chip exceeding 64 degrees. But from all that I have read, liquid cooling should give you a lot of flexibility if you decide to OC.
I thought I'd ask it here, while I'm at it: since the nehalem processors don't have a northbridge, what other components need to be cooled in an i-chip OC? As far as I know QPI has replaced it and is now "built-in" to the processor - could anyone enlighten me on what components now generate heat in a nehalem OC? Thanks :)
One last crucial aspect I think I should add. Double check the brand of the PSU you are buying. If there is one component that can either make your PC the best thing you've ever bought or an absolute nightmare, it's the PSU. It's like a strong internet backbone, without it everything else crumbles. Here I will have to enforce brand-buying. In the main, Antec, Corsair, Thermaltake, Cooler Master and OCZ make fantastic PSUs - if you can purchase one of them I would recomend it. There are many other decent brands out there as well: some Gigabyte and Zalman models spring to mind. But of the others, I've had personal experience, especially with Corsair & Thermaltake, and they are worth every penny of the added cost. Never, ever, ever, ever, never, ever, never (that enough yet?) :P buy non-branded PSUs... never :P
So, Captfitz, I hope that helps and wish you the best of luck with your new PC - it all looks great to me! If you have any questions about what I've added, please feel free to ask :) I should be having a crack at my first i7 soon, can't wait to start a new generation of OCing and put all my theoretical nehalem knowledge to use *grins*