PCB design for small dc motor actuator

This is for a personal auto hobby, where I have upgraded the bi-directional actuator motor to the vehicle throttle beyond what the car computer can directly drive before tripping out on over current. I need an intermediate controller to boost the pair of existing pulse width modulating (PWM) 0-14VDC 5 amp signals (A and B per attached block diagram) from the car computer, into an identical PWM 0-14VDC but 15 amp current capacity (A' and B'). Your design (in green on the second block diagram) will ONLY have inputs from A and B, plus power and ground for 14 VDC at 15 amps. You will NOT have any access to other vehicle control systems whatsoever. Your design must replicate the same input PWM signals A and B exactly and instantly, just with more amperage, and output only A' and B'. I will need to review your schematic design, and will need a PCB design and bill of materials for fabrication. This is a simple design so my budget is small, but I am not in a hurry. Thank you!