Yes, as long as you get the correct type of lamps for the fixture. Or, you can just buy the lamps at the hardware store too. Fluorescent lamps with a color temperature of 6700K or above are adequate for aquarium use.
thats exactly what i did with my tank. as you mentioned, use aquarium bulbs ie. take your light fitting with you and try the bulbs in the fitting before you buy
yes, but be aware that the moisture above the tank will eventually corrode a regular fixture. in my opinion its worth it to replace it with another cheap fixture than spending a fortune on a sealed plastic fixture. ~LiquiD~
if your using lids moisture shouldn't be an issue. The bulbs are a standard, so as long as your able to find say for example a 48" fixture would take a bulb of 46" and you would be looking for a pin setting known as t8 those are common bulbs and sizes.