for a nice intel rig I would build a budget rig thats really fast for editing it would go like this....
for 4 sata slots and NO raid I would get a:
Gigabyte P35-DS3L and Q6600 and 2x1 gig of ram (gskill NQs)
for 6 sata slots and Raid capabilities i would go with:
Gigabyte P35-DS3R and Q6600 and 2x1 gig ram
for a video card i would go with a 7600gt unless you need DX-10 support then opt for the 8600gt...no difference in cards other than that...
that will set you back about 500.00 or less