So im looking to upgrade from my 2500 Barton, yea i have been out of the loop

Basically what im looking for is a gaming built around the 2500 Barton of today. I could oc that sucker to speeds of a cpu's twice the price.
I want a sys that will stay strong for over a year if possible. My budget is $1300 and under. I have done some reading and come up with this. Please put any input you may have.
Cpu: AMD Phenom II x4 955 $229.98- From what i have read this is a great price/performance cpu
and a good oc.
Mobo: Gigabyte MA790X-UD4P - Worried about 2 ram slot being obstructed by after market cooler. Will a gaming sys ever need more than 4 gigs of ram?
Ram: G.SKILL F2-8500CL5D-4GBPK PC2-8500 4GB 2X2GB DDR2-1066 CL5-5-5-15 $67.99
or
G.SKILL F2-8000CL5D-4GBPQ PC2-8000 4GB 2X2GB DDR2-1000 CL5-5-5-15 $62.99
V/C: XFX Radeon HD 4890 XT 1GB 875MHZ $249.99 - Just going off what others have picked.
Cooler: Xigmatek HDT-S1283$46.28
Case: ? - Just something that will fit all the components with some room to spare
P/S: Corsair TX750W $124.99
Monitor: - Samsung SyncMaster 2343BWX 23IN $235.08 -
Prices are off NCIX, i know i can pp to get some prices down...