being that i work at Home Depot and IN the electrical dept where you saw the bulbs, i too have had this thought running around in my head for some time and have researched it quite a bit. true the bulbs woudl work, but the color temp is horrible and woud as stated above cause horrible algae blooms, and look like crap. What i WOULD reccommend doing would be to tlak to your electrical rep about ordering in a MH ballast in whatever wattage you want cause this can range anywhere from 20-50 bucks(much cheaper than fish retail online) from advance transformer. true they will be magnetic ballasts, but for the price you cant beat em. The MH ballast kit from advance comes with teh bare bones, a plug/cord, the ballast adn the wires to run to the socket. Youd also have to special order some porcelain Mogul based sockets, unless you can find them at teh store cause most HD's dont stock them...Next youd have to look at reflectors if you get soem of the newer reflectors, you can ditch the socket idea cause soem of them have sockets already builtin, which might work a little better for you...anyways, thats jsut a start. if your comfortable working with electricity, its not to hard to build your own hood/lightign set-up.
BTW, heres a cool link about how to build a MH ligh for under a hundred bucks! not sure if i agree with it altogether, but its interestign reading material!
http://aquarium.union.rpi.edu/rpi.html
good luck
jon
