Keep in mind that the speed floor is -90% and the recharge floor is -75%. You can slot slow enhancements to hit the speed floor with a single power, but you can't enhance -recharge so you need to stack powers to hit it (unless the power starts at -75%). If you want a controller, I think Ice/TA, Ice/Rad, Ice/Time, Ice/Storm or Ice/Cold could all do it. I had an Ice/TA back on live. You could also do it with a Cold/Ice, Storm/Ice, Time/Ice, Rad/Ice or TA/Ice defender.