The motor comes with a controller. It's made by SME, and is surprising small and light.

Who makes the motor, then? Where did you get the electronics side of it?

I want to design an electric formula car and am having some trouble deciding what parts to go with.

I used a Netgain Hyper9, which is a pretty decent AC motor. There are smaller, more powerful AC motors out there, but they can get pretty expensive. AC is nice for the regenerative braking. (When applied to electric cars, AC generally means 3-phase AC, synchronized with the rotation of the motor.)

On the other hand, series wound DC motors are cheap and popular for drag racing applications. Check out the White Zombie if you want an extreme example. The guy that built it lives nearby and he's been giving me advice on my (very different) conversion.