72 volt PDS conversion need help

[AGECS]

ok I'm doing my second conversion after successfully doing a 48 (8-6v batts) dcs conversion with 8:1 gears producing 30mph. Heres the deal, I have a few GE motors from gems and a advanced dc motor from a ford th!nk (both sepex) and a bunch of ge controllers and a delta q dqiq charger. What are my options for throwing this into a pds cart? I like togggle switches so I figured I could make a 3 solenoid setup for a rocker switch. My buddy told me the ge controllers limit speed because a gem/think should fly at 72 volts. I'm gonna throw a 6:1 gear set in the beast too. What top speeds am I lookin at? I really don't wanna throw money down to go series (alltrax axe controller and such) I also know the ge's can't do ITS so I was gonna use a marathon pb6 pedal or rip out the ITS and work in that pot box. Any advice would be apreciated to get the most out of what I got.