Just a few things to help you keep in mind when building your gaming PC.
Make sure that your motherboard supports your 1066 ram.
Have you got a big enough PC Case to house your graphics cards? some cards can be long and with a small case, you may have problems.
Its worth it to spend £70 on a nice big aluminium finished case designed with good airflow and organised interior wiring and layout.
Check out a nice CPU copper/aluminium heatsink with fan if you have not got one.
When you get one, choose one that is easy to clip onto your CPU and remember is there enough space to accommodate it?
Is your PSU enough? if you run a pair of graphics cards in SLI, you may need at least a 1000W PSU.