Controlling 4 motors With One Controller

I have an application were I am using 4 motors to provide thrust for a raft. There are two motors per side that will operate in tandem. I will be controlling the AX3500 via R/C and/or RS232. The system is currently designed for a 12V system. I have a few questions.

1. Can I connect 2 motors per port of the AX3500?
2. If not, can I control a chain of controllers from a \'main\' controller? (ie. 2 controllers 1 for each pair of thrusters)
3. Is there another model that can control 4 motors?

Thanks,
Jeff

There is no problem connecting 2 motors on an output. Just be careful that the total current will be 2 x this of a single motor. Select the controller accordingly.