That's one of the craziest things I have heard of for a while. I would look at the largest jets that you can fit in a board (why not buy a blank and form your own board and build to suit) You will need cooling for the motors which you should be able to get by inserting an aluminium plate/heat sink in the bottom of the board and have the motors come in contact with that for heat transfer by using heat transfer paste or similar. Keep the jet pumps as they are with no extra tunnel because of drag. Motors close to pumps and use batteries to balance board out. You will need a potentiometer or something to run brushless motors ( I am after something similar) Don't forget that water and electrics don't mix, no room for error so you will have to have everything well sealed. If you built your own board you could put aluminium stringers in and set everything out to suit the motors, batteries and jets. You might find that the easiest way to go and take less time and have a better end product you crazy bloke
