I have a 20 ft fishing model, and have a 70 lb trolling motor on the front. Works well even in a fairly good chop. I wouldn't recommend putting a motor on the back though, (unless you are going to backtroll) as boat control with an electric on the back is very difficult on a boat that size, especially with a cross wind.
I have the ped seats, live well, sonar and rod holders all around the boat.