"I know nothing about electricity, or wattage, or amps or any of
the stuff in that class I hated in college and had to take twice
to finally pass with a "C"."

I suggest two options:

1. Replace your present lamp with a 20 W plant-gro bulb - they
put out roughly 3x the plant growth light per watt as standard
fluorescents do. If you are willing to wait a bit, see
http://sankey.ws/plantlumen.html
I've asked for spectral data on a number of useful lamps,
including Westinghouse Plant-Gro(R), and will be able to give a
more accurate answer than "roughly 3x" once I get it.

2. Follow Mister Gardener's advice: go to a glass shop, get a
glass plate cut to match the top of your aquarium (leaving room
to use your current front lid) , then buy a complete 2 or 4-tube
rapid-start fluorescent fixture with the total wattage you want
that will sit on top of the glass. Buy some semi-gloss or matt
tintable metal paint for it, and get it mixed a colour you like.
(Everything electrical here these days comes in screaming white
....)

"Why do they even make the lamps if they aren't bright enough?"

The usual '10 gallon' kit here comes with two 15 W incandescent
lights that equate to about 1/3 fluorescent watt per gallon :-(
Obviously, to pet stores, aquaria are for fish, not plants.

Does anyone know of anyone other than Westinghouse that makes
plant-growth fluorescent tubes? I'll chase them for data if I can
find them.

John