I've heard setups both ways. I think with a passive crossover, using the same amps makes sense and in my experience sounds better. With an active crossover it will sort of blend the two or three amps sound's together so there may be less sonic differences in the end and should sound like one voice. I would make sure to use all the same cabling either way I think. Your system looks and I'll bet sounds awesome. My speakers, Legacy Helix, are quadruple amped using a Xilica digital crossover and are supplied with about 3,600 watts per channel. Talk about headroom!
You might want to check out my system as well.
You might want to check out my system as well.