For those of you that were wondering about v regs that can be used for this:

http://www.dimensionengineering.com/DE-SWADJ.htm

I've got the anyvolt as well as the DE-SWADJ. Both of them are rock solid and will hold whatever voltage you set them at. If I'm thinking right you could then use basically any 12v or 9v power supply with it, since it's a switching regulator.