There are good sources of agricultural T5's, but I can't think of them offhand.
This may sound super Luddite, but I personally prefer working under T12s (I was running 'cool white' with great results and recently started on 'daylight' which is even BLUER) in almost all cases for one main reason: The tubes run cool to the touch and if you neglect to raise the fixture in time, no prob, the plants won't scorch.
T5's are simply AWESOME for seedlings if you have the time to monitor growth and maintain a nice 2" distance from canopy to light.