Welcome to the Orchidboard, Pete.
Yes, it's true that chlorophyll absorbs light primarily in two regions of the spectrum, but pretty much all horticultural fluorescents emit in those regions. The color temperature is a bit of a descriptor of the relative intensities, however.
Some prefer bulbs with color temperature around 5500°K, as that replicates midday sun pretty well, with roughly a 50/50 balance in intensity of the two regions. I recommend the roughly 6500°K bulbs, though:
- Chlorophyll absorbs more in the blue end than red end of the spectrum.
- the blue:red intensity ratio is equivalent to a clear summer day with direct sun, plus backscatter from the atmosphere adding a bit more blue.
- Not only does the 6500°K bulb match the chlorophyll absorption better, but it emits with about 50% more energy flux.
As a discount reseller of Hydrofarm products, I sell a lot of their T5 fixtures. A 2-bulb, 2-foot fixture will provide sufficient light for phals occupying and area about 3 feet long by about 18"-24" wide. I'd put the paphs in the middle.
Indoor orchid growing
i thought i would have about 15 total, and keep it that way. well that was this summer and i now have around 40 
Hybrid Mode
