There are a number of electric outboards currently available with new ones coming to market. The Torqeedo 4.0, a 4Kw unit from Germany is expensive and they are missing the boat (no pun intended) by not having regen. The amount of thrust matches a 9.9, which is what is used on PDQ 36s. AquaWatt outboards have the physical dimensions of a 9.9 and come in two flavors, a 13Kw (a pair of these are over kill on the PDQ) and a 23Kw.
aquawatt green power electric outboard motors
Note the weight difference between these DC gen sets vs an AC gen set. You won't find an 8Kw AC diesel gen set for 290 lbs like this DC unit.