CFL's go upto 105w before you need a mogul base. They usually don't sell anything over 24w at hardware stores (but they label 100w equiv all over the front of the package). A couple 85 or 105w CFL's will be more than enough to keep your plants happy in that area and they can be picked up for about $20 a pop at a gardening store. If you're going with the standard hardware store CFL's, get a Y splitter so you can plug two cfl's into a socket and shoot for about 8 of the 24w bulbs. Cool white for veg and warm white for flower. Hope that helps!
Oh and remember just get as many as you can. If you can't fit it ideally, get a start and upgrade as you grow...