1. I AM IN LOVE, with the FN2000 (such beautiful accuracy, and full-auto!)
I was never a big fan of that rifle in any of the games. The AS VAL (or whatver it's named in Stalkerish) was my favourite in vanilla CoP, in no small part due to the fact that you can upgrade it to maximum accuracy. That actually broke the game a bit

2. Where to get my SEVA suit, nimble or mr "ALOHA!" from the yanov free station
Nimble's is simply more expensive, iirc. Some people would argue that Nimble's is technically 'better' because in comparisson the Nimble SEVA gets green bars, but honestly even if that isn't a bug of some sort the difference would be unnoticable. It really doesn't matter.
What should I do? Should I play CS or CoP? If it's Clear Sky I need a mod that makes it less boring and frustrating than vanilla. For CoP, just something that changes the game enough to make my 2nd playthrough enjoyable

I would personally recommend finishing Clear Sky. In 2 hours you couldn't have gotten very far.
The Complete mods are always easy to recommend. I personally use Redux for CoP, but it's not to everyone's taste.