We have been transforming a 12 feet aluminum dinghy into the "Dingy Mobile".  It is rated for 660lbs and a 15hp motor.  Unfortunately, my kids are growing toooooo fast and it may not be big enough for all of us.  Both kids, although just 13 and 11, are over 125 lbs each.  Devon, just turned 11, is wearing size 10.5 - 11 size shoes!!!!  We haven't test run it yet with the 10 hp motor.
Things we have done to it:
1.  Attached an old fire hose around the rim.  Fender protection.
2.  Attached cleats to the front for lines.
3.  Fishing pole (or net) holders on the stern.
4.  Attached a quick release boat hook.
5.  Got oars.
6.  Added another piece of wood to the sturn for the engine support (sorry Mark, I ripped yours off).
7.  Added seat cushions.  Some old camping sleeping pads wrapped with marine sumbrella imitation fabric with snaps.
It keeps the heat down and because the sleeping pads were closed cell foam, water is not an issue.
8.  We got a fish finder,(not installed yet).
9.  A new plug/Anchor and line.