They are great lights.
Depending on the wattage you are after, 20 - 30 watts would be good. If you like it really bright, go 50.
I prefer the cool white, but that's just my preference.
I use the 12v 20watt flood lights when camping, and run them from my camper. I generally don't want lots of bright light, so I normally point them up into the trees for some mood lighting...
