Finally grabbing a computer, wondering what else I need

[Choofers]

One of my classmates showed me a local ad on craigslist, a guy is selling his old build, minus the psu and a hdd. Some parts have cooling, but I think he kept his old cooling for his new build.

I'm definitely gonna go for a SSD, probably gonna stick with something small because most of my data (ie music) is all on a 500GB external.

This is what he has up for grabs.

Mobo: XFX nForce 780i with a north bridge fan.
http://www.newegg.com/Product/Produc...82E16813141005

CPU: Xeon x3363 quad-core @ 2.83 Ghz
http://www.newegg.com/Product/Produc...9SIA1PR0U06364

RAM: 8GB Kingston HyperX
http://www.newegg.com/Product/Produc...82E16820104108

GPU: 3 BFG GTX 280s in 3-way SLI
http://www.newegg.com/Product/Produc...82E16814143141

Mobo and RAM have fans, CPU has a heatsink. He has this posted for $320, wondering what else I need to get to make this run optimally. Probably not gonna overclock until I understand more about it.