third..what's more efficient for FR, blacklight incands or blacklight fluos?
By far, an incandescent. And you dont need a blacklight one. You can use it, but it use high K to get some UV emission, and it results on a way reduced FR emission. I think people uses incand blacklight to avoid getting a filter, due they emit very little on the visible range. But im not sure at all that they filter all visible light.

A filtered standard incand is the cheaper and more efficient way of adding FR.

FR leds arnt very efficient, but decent enough. And for experiments with 1-2 small plants, you would need little. I believe LEDEngin has released 740nm leds recently. Roithner-laser has them too.