Yes you are maxed out on slots, 24 Gun, 48 Ship and Suit.

Getting resources to fix your ship, I can tell you the easy way, fast way. If you know how the "Orange Beacons" work, (the ones with the orange beam of light coming out the top). Use a "bypass" chip to access it, pick "transmisions" Keep repeating until you get a "transmission tower," go to the transmission tower, inside use the device, and it will show you a "crashed ship." Go to the ship it will be a 48 or 47 slot ship. Park close to it so you don't lose your track of your current ship. Accept the crashed ship dismantle everything, and take the resources. You will get everything you need to fix your ship and more. Here is a video how to do it:

https://youtu.be/2B9XzLhu-OM

yes it's a good strategy, and that's why the modules were broken on my current ship - it was a wreck i found on a rather nasty little planet, and most of my other ships were originally crashed wrecks too.

putting them back together is usually straightforwards, but this particular ship has been a real arse to fix and the last few places i've visited didn't have what it needed - the last planet had one tiny little spike of aluminium though i never saw any more, and never found any in space either. killing sentries gave me the rest of the required aluminium

as you say, wrecks are normally great for upgrade resources, and dynamic resonators were quite common... until i needed one, that is. they've disappeared from the galactic market too



...and tomorrow or the next day i'll decide to swap ships again, and the whole exercise will begin once more

Also try talking to the NPC's that land at the Space Station or Trading Posts on planet. I was able to buy Atlas Stones (very expensive) form an NPC, to replace ones I lost do to dying and not going back for my stuff.