since you are only using two lights i'd go with two cools then two warms and swap em out. Since you are probably going to goto some random local big box store the most you'll probably be able to find are the 150watt equivalent bulbs(23watt CFL if my memory serves me correctly), try to find those if you can, the more wattage the better...
You can get spring loaded clip reflectors cheap at walmart for like $6-8 i think...bought one to heat my chickens water in the winter outside a few years ago. If you can also get a small fan to keep some air moving around...if you close these all in you'll start to have some heat issues. What type of area are you going to be growing in?
Also...keep the CFL's as close to the plant as possible without touching it, usually about an inch. You will probably have to adjust them frequently, and don't expect to get much for yield out of this endevour...two CFL's, unless they are supersized ones, wont get you much...