Hi. First of all, I recommend the article on lighting in the greenhouse forum. You would do best to get "cool white" fluorescent tubes. I'm not sure if you meant you plan to get a red and blue bulb, but that's definitely not necessary.
As a fellow dormer.... erm, isn't that a kind of window?... i can tell you what i have to give you some ideas. Perhaps it will be useful to others, so i'll post some photos to demonstrate eventually.
There are two or three options.
1- Terrarium
2- Grow shelves
3- Window w/ supplemental lighting
Note that these options aren't mutually exclusive.
For example, i have:
(1 & 3) 2x 10 gallon terrariums (one on top of the other) right against the glass of a NW window. In the top tank (which is open) are most of my large sarracenias. Even though they stick out the top, they get slightly higher humidity that way, which seems to help prevent burning of the pitchers. In the lower tank are my lowland neps and other low-light tropicals light D. adelae and D. prolifera and U. calcyfida.
The light for these plants is supplemented by a 150W High Pressure Sodium lamp, which hangs from a converted torchiere lamp post (because i can't drill my walls or ceiling, either). The HPS lamp comes on at sunrise and turns off at 11:00, when the natural light in the window becomes bright.
There are also some intermediate neps and sundews sitting on the windowsill, and a bunch of utricularias. This is only an option if your dorm isn't horrendously dry during the winter months. It depends a lot on the climate and geographical location of your school.
(2) For all the shorter plants, seedlings, and those that need lots of light, i have a grow shelf. You can buy a nice set of metal shelves (at the local hardware store it was $80 for the whole unit, but you should be able to get it cheaper at superstores or outside of this gouge-a-rama city) with four shelves and 72" poles. The shelves are 4' long, and adjust on the poles with semi-cylindrical plastic collars that fit into grooves on the poles. Quite nifty, actually. Anyway, i have two $7.50 Home Depot 2x 32W 4' (F32T8) shoplights with electronic ballasts that i hang from one of the shelves, and it makes a very nice grow shelf.
To answer your specific question, i'd recommend getting the shoplights i described, but you'll need a shelf that lets you hang them above the plants. You might be able to stack up some bricks or build some simple wooden "feet" for either end, and set the lights on those. Remember that the lights don't have to be over the plants. For tall pitchers like leucs, you might put a fixture against the windowframe (vertically), so that the whole plant gets sufficient light.
I hope this was in some way helpful. Let me know if you have any questions, and good luck.