This is my first time building a computer and am a little lost. I've been reading a bunch of literature on the topic and have replaced almost all the parts in computers many times. However I knew all those parts went with each other. However making one on your own has the drawback of not knowing all these parts work together. So I was wondering if someone could help enlighten me as to the art of building or anything I should read. This is the current build of the system, I have Vista x64 Home Premium and a 500gb HD with a 16mb cache. Anyone who could please tell me if this will work and if it's good I would greatly appreciate the help.
Oh...my apologies, I forgot to mention the budget. It's only $1100. I already got the CPU, I just put it in there to show that it's part of the system (There was an awesome deal for the Q6700 for $210)
I think you should go with Dual HD 4850s, given the fact your board is limited to x8/x8, if you crossfire HD 4870s the bandwidth limitations will show greater loss compared to HD 4850. Add to that the fact that you can get 2 HD 4850s for $340 before rebates.
The X48 is basically a higher binned X38 chip, so don't bother with them, since an X38 can do 98% of what the X48 can do at $100 less (and that really only applies to overclocking). Both will give you the x16/x16 bandwidth required for HD 4870 crossfire.