The two bulb solution is a incandescent bulb & a daylight fluorescent bulb
OR a wide spectrum fluorescent bulb & a plant grow light.
There is another forum dealing with growing under lights they will be able to offer other suggestions

Does the light fixture come with a ballast, if it has a ballast and has a mogul base (bigger than standard socket) it needs a HPS or MH bulb.

the cheapest plain old fluorescent bulbs you can buy ...

replaced once per year ...

and the only variable in my experience.. is keeping the bulbs within about 2 inches of the plant ... meaning the fixture or the table has to be adjustable as to height ...

its more about INTENSITY of light.. rather than type of light ...

this is based on hosta.. annuals.. and conifers

ken

ps: bottom heat doesnt hurt either.. if you are in the basement ....

There are lots of variables that need to be taken into consideration for a proper answer. I'll give you one simplistic, but hopefully useful, answer...

If you are doing this temporarily and want to do it for a reasonably inexpensive price, go with fluorescent fixtures. The type of light is VERY important. Wavelengths (specified in degrees Kelvin), too short or too long, can have a considerable negative effect on plant growth. I use T12 bulbs in the extra-cheap workshop light fixtures they sell at Home Depot. Each fixture holds 2 bulbs, and I place the fixtures as close as they will go (with the included reflectors in place). Each of my 4' x 1 1/2' shelves are covered with 3 fixtures (6 bulbs). I use a mix of 4100K and 5000K bulbs. This setup gives a result pretty close to natural sunlight*. The cost of the bulbs and fixtures are about as reasonable as any possible new-equipment solution.

* Natural sunlight (depending on how/when it's measured) peaks at a little lower wavelength (higher temperature) than the 4100-5000K, but the best effective spectrum for most plants is actually pretty close to the values I use. The reasons are probably a little technical for this discussion, but I just wanted to point out that there is a reason to use somewhere around the temperature range I mentioned.