1998 Cushman Minute Mizer Conversion

[Tsuntsu]

Hey All,
I am new ti the group but have been doing some reading. I am looking to get an old minute mizer going and add a full cab to it. I am going to title it as an assembled vehicle so I can legally drive it around town and to work. I just had a forklift company come look at the cart. It's a 24/36v cart with a curtis 1207 250a controller. It is currently wired at 24v but both the controller and the motor are rated to 36v. Unfortunately, even at 36v it is only rated to go 17 miles per hour. The Forklift company said it needs a new controller and both forward and reverse solenoids. I am new to electric vehicles and don't want to make an expensive mistake. Since I am replacing the controller anyway, am I better off going with a 48v higher amp controller from the get go and overvolting the motor? not sure where to start, but excited to get moving.
Thanks!