Eric,
The Cruise Controller will work without the brake switch, but as you say, without regen.
All of the cruise controllers can handle up to 60V, the only difference between the three variants is the low voltage cut-off.
You would need to email sales@goldenmotor.com regarding the 48V Regen controller to see if they are available or not.
(I see the 36V version is $20 more than the cruise controller).
The wheel locking does work with your motor, but not with the geared minimotors. (or the current Magic Pies)
The cruise controller should give you a better range than the regen only one, as it will enable you to coast with the throttle fully released, whereas the regen one automatically activates regen when the throttle is released, meaning you have to keep the throttle partly activated in order to prevent unwanted deceleration.
In my opinion, the cruise controller is both cheaper and better, but you must decide what suits your specific needs best. (If it is still available in a 48V version)
The cruise control is a nice feature, but to use it safely, you would need to have your brake switch installed.
Alan