Might as well go 955. The 975 won't get you anything that justifies its price.
Eh. Stay away from Thermaltake PSUs. That one'll probably work, but I generally advise sticking to the golden list:
and a few more at high wattages (Thortech, NZXT, Ultra), but that's not important here.
A Ti would be happy on a good 500W PSU. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Lastly what is your budget and you would get better information if you post links. I for one don't want to spend the time looking up all those parts on newegg. If I am spending my time helping you I would appreciate it if you could spend the time to post the links. (Please don't take this the wrong way)
I looked at the 2500k actually, and I like it. But the 2500k+a nice ASUS (Must be ASUS) Mobo didn't fit my budget. And I prefer AMD CPU's anyways. As I have been running a comp for 3+ years under stress quite a few times with no problems.
I bought a on sale A6-3650/gigabyte crossfire mini atx board combo.
Reused existing hd-4870 cards, ocz Fata1ly 550 watt, arctic cooling 13 pro, 3 12cm case fans on med-low. winxp pro dx9.0c.
135fsb, 3.51ghz, 550mhz 320 shader clock, 31c was the highest apu temp even when trying out the integrated gpu running prime95+furmark. The system tested stable with the integrated and crossfire 4870's.
If you run the computer at high loads fairly often, this much cooler running chip might be better then the hotter running phenomIIx4.
The A8-3850 would be a bit faster.
I tried out the integrated gpu, gaming at 1080p, i left the game settings where they were set with the x2-crossfire setup i had before. Games like dirt2 ran at 24fps, most other games ran, some well, a few were a bit choppy but the game did run ok.
I would say the integrated gpu is on par with my former ati x1950pro pcie card and close to a hd-3850.
I would consider going to a cheaper case, micro atx z68 budget board, i5-2500k and then a hd-6950 because they use less current so you can use a cheaper but decent brand like antec, corsair, ect. 500 watt to 600 watt you find on sale somewhere.