You can use the Edison Module with the mini breakout board for this. If you want to use 4 pins for PWM you can, the module has 4 pins for this:
J18 - pin 7 : GP12_PWM0
J18 - pin 1 : GP13_PWM1
J17 - pin 1 : GP182_PWM2
J18 - pin 8 : GP183_PWM3
I suggest you to use a shield with drivers for the motors; with this you will be able to manage the current and voltage in the motors. Take a look at the Shield Testing Report, you will find some examples with motors that may help you with this.
Also, take a look at the Hardware Guides of the module and breakout board.