Need to control 4 x 48VDC/20A dc motors

Do you have a controller with the following specs:
We have 4 DC permanent magnet motors rated at 1KW, 48VDC, 20A continuous, and 40A peak.
We do NOT want to control the motors in velocity or speed control mode. We require the motors to be controlled in Current or Torque control mode.
We require either a drive amplifier rated for the above or a combination of amp/controller. Ideally we would like the controller to be interfaced with a CAN bus if not we can live with a RS-232 comms link.

We can do a 48 Volt controller as special order; a minimum quantity is needed. It would be an RS232 controller, as we do not have CAN yet. One controller would drive two motors. What sort of quantity do you anticipate?
I assume you will be using a micro-controller board with RS232 output.
You would need two motor controllers, so the micro-board should have two RS232 ports, one per controller. With our controller the micro-board can read the motor current via the RS232 port every 16 milliseconds (to be more specific, you can query the current approx every millisec, but a change of current (command) can be issued every 16 millisec); its software would have to adjust the motor drive accordingly. Would it work for you?

The quantity required would be four controllers, we would have 2 on our robot controlling the four DC motors and we would carry 2 as spares. This is a custom project hence the unique requirements and low quantity.
The RS-232 would be controlled by a PC or a dedicated micro-board.

Being this a special product for us, the minimum qty we require is the area of at least 10 units.