Comments on New Gaming System (<$2k)

Ok so I'll briefly introduce myself, first thread, long time lurker, and an Aussie (hence part value will differ for some)

So I'm building a PC for a mate, he's cost conscious but still splurging on pieces I suggest. He's got a 2-3yr old custom PC, he wants to upgrade, so we're keeping all the components that aren't gonna help with performance (psu, case, dvd burner etc)

I've come across the following pieces, just would like to get a community opinion if that's ok with you guys  

CPU - AMD Phenom II X6 1090T - $353

Reason: Picked a 6 core CPU with high clock speed with the hope that future applications will take advantage of multiple cores (mainly games). Of course I've read the Turbo Core speeds up 3 cores up by 500mhz and slows the other 3 down to 800mhz (or visa versa). This will take advantage of single core applications? I've read PC mags about it, but this is my first time implementing new tech.

Mobo - Gigabyte M4A89TD-PRO-USB3 - $210

Reason: Future proofing, USB3, SATA 6gbs, room for another Gcard if need be. Cheaper than other models that have less.

RAM - G Skill 4G(2x2G) DDR3 1600Mhz PC12800 9-9-9-24 - $136.00

Reason: 1600mhz is the speed the Mobo can take, don't know a thing about OCing memory so staying away ha ha. (If it was my own system I'd give it a shot)

HDDs

Primary - Scored a 128gb SSD off ebay for $250 AU which is a deadbeat bargin.

Secondary - Samsung 1.5TB - $111 - best price per gigabyte atm

G.Card - XFX 5870 1GB - $520

Australian PC magazine reviewed this (but the 2GB version >:| ) and was their top choice, i enjoy ATI's products and this is good value for money before investing half the budget in a G.Card (5970 etc).

All prices are from a aussie pc store (www.umart.com.au)

I'm doubting the 6 core against something like a i5 that has the same price. This is what I need advice for.

NOTE: No over clocking for this system, just going to be standard and for a gaming rig.

Cheers in advance guys.