Barts:
IMHO, the best, simplifying solution right now for active speaker making is to use a plate amp with built in DSP. These are available from Madisound, Parts Express and miniDSP.
They come with 2 or 3 output channels. The benefits are mulitple, including not having to have 3 amps and an explosion of cables coming in and out of them, but also better frequency response tailoring than you get in an analog crossover.
I am currently working on a 3-way center channel and the features of a Hypex 3-way amp/crossover is really outstanding.

