I have recently had a side-power one fitted on a new 36. I have has side-powers on the last 3 boats and they have always worked well and been reliable. Should be plenty of room for the tunnel and gubbins under the forward berth inc the batt on yours. Osmotech (I believe) are agents for side-power and are normally very helpful. Mine was done in two stages. A glassing GRP specialist put the tube in and seated the motor and an electrical guy did all the cables, batt, switch and chargers etc. One thing the electrical guy did say is to ensure that the battery is as near as can be to the motor - short cable run - and that its box or container was reasonbly sealed but properly vented outside.