Year old rig?
First of all, Biostar is a cheap brand but on the plus side ive never had issues with them.
Very risky on CPU, glad its working but always expect a failure.
GPU is great. prices are cheap enough, SLI that bitch
Ram is cheap. Get another 8gb kit unless you have 4 sticks of 2gb. if so, invest in a 16gb kit. 1333 16gb kit wont be to costly
PSU, it it works dont fix it. And 700watt will SLI just fine
HDD's are super cheap. Drop the 160GB, buy you a 120gb SDD for boot and installs like wow/office, and keep your 800 or drop 100 bucks and get a TB 7200rpm 64meb cache seagate barracuda
If the cooler works Great, if you need better performance, look into the Noctura 14z i think.
Very nice build. Deff room for upgrade but at the same time will last you for quite awhile