PSU/GPU/CPU cooler Gaming PC advice

So, here is the theoretical build (to be purchased in september). Parts are subject to change, but i am trying to learn about this stuff so that i may make an educated set of decisions when the time comes.

(Gaming PC with intent to livestream frequently on twitch.tv)

Case - Corsair Carbide 500R
Processor - Intel Core i5-3570K Ivy Bridge 3.4GHz (this is more or less official)
Mobo - GIGABYTE GA-Z77X-UD5H LGA 1155 Intel Z77
Optical drive - generic (future blue ray)

This setup with below PSU and GTX 570 is roughly $1,000 through newegg+ a couple of combo deals (not including the RAM/Hard Drive because i already own them)

Salvaged from previous PC :
Hard drive - Seagate Barracuda 7200 750GB 7200 RPM 32MB Cache SATA
RAM - 8gb Kingston HyperX 2GB 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
GPU- EVGA GTX GeForce 550 ti.  Sadly, i know i will need a better one to run the games i want such as bf3 and crysis at a desired 45+fps always.

I game on a 1600:900 monitor with a larger 23 inch (P.O.S.) monitor next to it

Now, the questions i have yet to answer..

Which GPU?
Im looking at the GTX 570 and the Radeon 7870 (I will upgrade to a larger monitor later) any other reasonably cost efficient suggestions, and is the 7870 just too much card for my purposes?

Which PSU?
looking at the CORSAIR Professional Series Gold AX650 650W ATX12V 80 PLUS GOLD Certified Full Modular
- is 650W enough?

CPU Cooling.. seems to be the most vague subject i read about and i honestly have no idea if stock will work or not
- Now, i am getting a K series processor because i want the option to overclock therefore i know i will need an aftermarket CPU cooler.
- Bad airflow and air conditioning in this room desert climate no humidity lol. worst case probably 80°F in the room hence the well ventilated case.
- Corsair H series or no?