Converting from a non-PWM H Bridge to PWM

I have an antenna rotor DC motor that draws 7-8A continuous (~10A turn-on) and is controlled by a proprietary controller. I have reverse engineered the controller and it uses a PIC18F to switch two PNP transitors which in turn switch 2 half H bridges consisting of pairs of IRF540N and IRF5210. I checked with a scope and there is no PWM just direct gate control providing on/off and direction. It has a small 5v regulated supply for the PIC18F and I have powered it all with a parallel pair of deep cycle 12vdc batteries – these provide 240 A-h and can turn the antenna motor for hours of use. The motor turns too fast for my needs even with a 35 lb antenna load so I would like to replace the controller with somwthing like the Pololu High-Power Motor Driver 18v25 CS. Is this a simple swapping of controllers? Can any DC motor (I assume is is a brush DC given the speed, torque and weight load it can carry (75lbs) be driven this way by PWM or am I looking for trouble?

thanks in advance for any advice

Hello.

If you are generating the PWM signal, you should be able to use our high-power motor drivers with your motor. Alternatively, you might consider using one of our Simple Motor Controllers. Our free Simple Motor Control Center software allows for quick configuration over USB.

In general, brushed DC motors can be controlled via PWM.

- Jeremy