Well, for the price of two Mamba Max's, you can get a Mamba Max and a 1940. Should be plenty of power.
or for a little more $$$ you could go with the more powerful 1950
you may also want to try a neu motor
Nice work by the way i have very basic knowledge of CAD since i just started last week
That frame work looks nice, the very front looks like it needs a little more strength, i have been messing with 3d cad programs in school and at home for nearly 5 years, i probably have some i could host if you guys wanna down load them