GeForce Experience and ShadowPlay are available for all modern Nvidia GPU's. It makes proper game settings & recording/streaming super simple with almost no performance hit. If you want to record or stream, it's a good alternative to using a software recorder which relies on the CPU and constant framerate.
PhysX is Nvidia exclusive which can add a lot of visual elements to a game. I'm playing Borderlands with a friend who recently switched from AMD to Nvidia and he's constantly remarking how much stuff is happening on screen that didn't on his AMD card.
Each has their own versions of AA/rendering technology, multi-screen support and now variable framerate sync. Both the cards you're looking at should have at least some level of DX12 compatibility.
Ultimately, though, you'll be fine with either. Recent discussion on the topic.
As for cooler- if you're planning to overclock you'll definitely want an aftermarket cooler. As for which one to buy- just read up some reviews and figure out what you want. Be aware, though, that fitting an after market cooler in your case can be tricky- some air coolers take up a lot of space over your cpu/mobo (height & width), closed loop liquid requires a space to mount the rad/fans and run the lines.
I'm not well versed in the whole argument but every time it comes up I see responses like this:BlackIce wrote:7) CPU's - The FX 8350 is $160, and the i5 4960K is $220. That's a pretty big difference, but I'm not seeing much of an upgrade in performance, especially with overclocking. I know people love Intel, but I'd need some pretty serious persuasion to spend that extra money.
http://www.tomshardware.com/answers/id- ... wdown.html
Intel's processors perform better for gaming.