When I get home I can find the link to the DIY driver for LEDs. Using a power FET, controller, and a few resistors is all, you can make the driver for a few bucks compared to what they want for retail drivers.
For a power supply I just ordered a 200W adjustable laptop power supply, mostly because with those Cree LEDs you end up with a lot of wasted power driving them with 12V just because of how they multiply out. Also, the spare PSUs I have are all of questionable quality and life remaining.
For instance, with your 8 lights you would have to have 2 sets of 3 and 1 set of 2. Which would mean the driver for the 3 LEDs would have to drop about 1-2Vs, and the driver for the 2 LEDs would have to drop closer to 5-6Vs, which will require larger parts on your driver and less overall efficiency.
As an aside, I've got those exact same LEDs ordered from dealextreme.com. Its been about 2 months now and they still haven't been shipped. The flashlights I ordered at the same time are here though. I ordered 14ish of them and they have been listed as pending supply for a long time now, so I think they have some and thats why its not listed as out of stock, but not that many.