there are many sites online where you can order cfl's with wattages much higher than 42. i think they go up to 200.
as for the desk lamps, that sounds alright.
there are also clamp lights that are a lot smaller and easier to position. they are just light sockets with a clamp and cord attached to them. for aquariums and stuff. make sure you get the "V" joint for the lights so you can put 2 lights in each lamp.
as for C02, cfl's do not produce enought light energy to process any more than what the leaves are already doing. so dont waist time on that.

in dealing with circulation, is there any way to the attic from your closet? or could you "make" a vent to the attic?

you should try to get a soil mix from a local headshop. they are usually inexpensive and work great. and just get an all purpose vegetative growth fertilizer from the headshop as well. works great for soil mixes.

lowryder sounds fun and interesting, if you decide to pick it i cant wait to see your thread.

by the way, i hope i am helping. im not too good at this, but i know a little bit about cfl's