Types of motor controllers that can handle 3A+

tawandapro:
should i just use the ESC'S that i am using on the 4wd rover instead? The pololu ones are pricey plus the postage will drain my budget

No idea - what kind of ESCs are they, brushless or brushed? I presume your gear motors will be brushed from the discussion
above but you haven't given details of the existing set-up.