But I have no idea about motherboard or RAM. I was planning to get another ASUS board, but not sure which one. I will probably do some overclocking, and although I can't afford SLI at the moment, I would like the option open for the future.
What about cooling? I've got a big fan on the side of my case and a couple of internal ones, but is it worth getting a special CPU cooler?
Any suggestions or advice would be much appreciated.
To start, you should get the i7-930. It's an upgraded version of the 920, and should cost about the same.
Second, if you want to be able to SLI the 480, you'll need a bigger PSU. The 480s are crazy power hungry. You'll need at least a 950W unit.
For the motherboard, I would get a Gigabyte GA-X58A-UD3R. It's pretty cheap (for X58 boards), but it's a high performance, high quality model that's packed with features.
For the RAM, get any non-OCZ 3x2 GB 1600 mhz CAS Latency 7 sticks. G.Skill, Corsair, and Mushkin are the top brands. Don't get OCZ because they have compatibility issues, especially with Intel builds.
On cooling, you don't really need anything other than the the stock case fans and stock CPU cooler unless you plan on overclocking. If you want to OC, you'll need a CPU cooler. Some good ones are the Coolermaster Hyper 212 Plus, Scythe Mugen 2 Rev. B and the Noctua NH-D14.
Don't get OCZ because they have compatibility issues, especially with Intel builds.
I dont think its compatibility issues as they also cause problems for AMD systems. They just dont really work at their listed ratings, which makes it a PITA to get them running stable if you push them anywhere near their listed performance specs. In any case OCZ is not recommended unless you enjoy spending hours fiddling in the bios, struggling to get your system stable.