I've found that for small enclosures, you may as well use incandescent bulbs because plants need all that heat. While incandescents are supposedly "less efficient", an incandescent is no more less efficient if you are also using an electric heating pad inside that enclosure. 100% of the energy is converted to both heat and light. Fluorescents and LEDs don't really generate enough heat to keep it warm enough in there during winter time. I'm talking about inside the house.
(For those of you who might not know, halogens are just a different form of incandescent)
The only exception might be if you have multiple shelves inside that enclosure, with multiple different lights for each shelf, and in that case something like LED grow lights may be able to keep it warm enough, especially if combined with another type of light.
I've also found, that in actual practice, the type of light source doesn't seem to make much difference. The plant mostly responds to the amount of light. But blue light, especially the light from a CFL, is more prone to cause leaf burn at higher light intensities.
Theoretically though, I think the plants respond positively if a white light source supplemented with 660nm deep red light. Generally, you'll do best to avoid lower color temperatures, but I'm not sure plants benefit any more if the color temperature is above 4000K. It's true chlorophyll absorbs blue and red light most strongly, but that also means other color wavelengths can penetrate deeper into the leaf layer for more even and fuller photosynthetic conversion. I think adding a little bit of white is more efficient than using just all red+blue.
In terms of optimal efficiency, there are two photosynthetic peaks, one at 660nm and one at 620nm, so in terms of achieving optimal efficiency, you would want to target both (maybe in a 2:1 ratio or something like that). Generation of blue light from LEDs today is very efficient, but unfortunately blue light has the most limited leaf penetration, compared to other wavelengths, so that means it's only using some of the chlorophyl (and remember plants are also more prone to leaf burn or leaf bleaching from too much blue light).
The orange-red spectral line in a common fluorescent is very close to 620nm, if you did not know, and in any case I don't think 620nm is all that imperative if you're already supplementing with 660nm.
If it were up to me, I'd be very satisfied with a 4000K or 5000K light source supplemented with 660nm deep red LEDs, maybe in about 20-30% ratio.