A good rule of thumb is to always have 30% "reserve" in your power supply, at least on a high end gaming rig. Here are some reasons:
1) You want it to work on the hottest day of the year, where its output could be a lot less than in ideal conditions.
2) Capacitor aging can decrease the output...
Short answer: No. You cannot install two different nvidia display drivers at the same time.
Long answer: Kinda. There are hacks out there to make the driver think that the Quadro is a Geforce or vice versa, but that kind of makes me nervous given that a workstation usually has to be 110%...
Nice price! Too bad you still can't find a combo for less than $100, since the i3 2100 beats this in many tasks while using less power.
If you can overclock this a bit and unlock the extra cache, it might be a helluva deal.