Home Made PWM DC Motor Controller

I want to save some cost on the controller so I'm considering making one.

Here are my constraints:
1) Time: I'm doing an EV conversion for a school design project so I have about 3 months.
2) Familiarity: Neither myself nor my team members have electronics knowledge beyond basic RC circuits.
3) Needs to handle 96 volts and peak current of 400 amps for 1 minute and continuous amps of around 150 amps.

Would this be a do-able side project given our knowledge and time constraints? Is there a particularly helpful website for "controller design newbies" (such as myself)?

I read somewhere that if you want to design a controller that operates beyond a certain voltage and amperage, the controller design gets much more complicated. Would this be the case for our constraints?

Any help will be appreciated!