Boat Motor Holder

Any suggestions for motor holder on Troopy we have a rhino rack for the boat but where do you put the motor( Ten HP Mercury) when we leave the caravan ( will fit bracket to front of Van ) but to go inland with just the Troop to do some fishing and camping. Has anyone fitted a boat motor where the wheel on the troopy wheel sits at the back and do you need a steel ARB or similar back bar set up to be able to hold the motor or would the normal market bar hold starting to run out of money for all the things we want but want to do it safely.

would welcome suggestions
Cheers
Noel & Pam D