2 seperate amps for sure..... that way you arent restriced to the same frequency... i would go with a 2-channel amp (that has around 300 rms) then i would go with a mono block or a 2-channel amp that pushes at least 1200 watts (600 per channel if its...
2-channel amps are designed for two speakers and 4-channel amps for 4 speakers. You can usually bridge a 2-channel to one and a 4-channel to two channels. This will half the impedance of whatever the speakers are.
If you have two 220w amps at 4 ohms and you connect one to one 2ohm voice coil and the other to the other 2 ohm voice coil the wattage will not be the same, it will increase due to less resistance. you must be sure that the amps you have are stable a...