Nothing special needed aside from the coupler to attach it to the shaft. Off shore electrics just takes the stock motor mount and turns it around when using their flex coupler since it is longer than the stock joint. It moves the motor back to give more room for it. Seeing as how my boat stays perfectly flat in the water, I wasn't big on the idea of moving the motor even more forward, but after sepaking with them about it, they claim to have no issues with the weight being shifted.

As for waterproofing, you could do the typical bagging of electronics and such to make it resistant, but there is no sealed radio box. Mine stays bone dry inside after a run though. If you were to capsize, that's another story- but the boat is very stable, so I don't think that would be an issue. You could tape around the hatch with vinyl tape (electrical tape) if you want to seal it off completely if you are concerned about it, that is what I do with my H&M electric hydro. The tops is held in place by two plastic "tabs" in the front that slide under the front lip of the opening and then the velcro holds the back down. Oh yeah, it also has a stick on foam seal around the hatch to keep water out too.. It runs on a single pack and mine came with an electronic controller. Good luck.
Joe