Price range?
You can build a budget gaming rig for pretty cheap(sub 500) and even cheaper if you are recycling parts.
post a price range and I can dig up what some of higher end gaming cards are(ive been helping some friends look at video cards for months now)
you missed the part where he said gaming. YOu can build a better rig then buying a mac any day of the week. That and you would have to run d0ze in boot camp bc like 10 games support Macosx