Overclocking nowadays isn't dangerous at all, as long as you don't overload your cpu with too many volts (most motherboards are incapable of this anyways). A dual core gives no performance boost to dolphin because dolphin is not programmed to run in SMP. I have an Athlon 64 X2 4400 at 2.7GHz, and my framerate is not better then anyone elses.
Also Quadro's are useless unless you do things like CAD and 3d modeling. They are generally based off of GeForces, but sell for 300%-500% more then the comparable GeForce. Also not all GeForces can be modded into Quadro's, the 6800s were the easiest to mod however.
