Re: 144V controllers
You'd require a Permanent Magnet motor to use the regen feature on that controller.
Most EV motors are Series Wound Motors, which to my understanding there is no way to have actual "regenerative" breaking from these motors, only forced motor breaking which takes up energy.
Those Kelly controllers look good for $900 you get 144v and 250A continuous, fully programmable, current limiting controls, high pedal disable.
That's everything you need in an EV.