If you are thinking about an outboard, here is a link to my setup with an Island hopper motor. It works and I haven't had any problems but I feel I should have bought the Honda 2.3 hp.viewtopic.php?f=69&t=40482
The motor mount is just PVC tubing with two steel rods thru, glued into a 2x4.
The setup (and motor) that I really like is on this thread ( viewtopic.php?f=69&t=47001
I really love his motor, and he has a really well done motor mount. If I can ever afford to get a Honda, I will make a new motor mount like his (my current motor mount would not work with the Honda).
We go quite a way out at times, mostly down in the keys (mostly scuba diving), where some of the reefs are 5-6 miles out. Many times a good day for us can cover 50-60 miles total, so we kind of need the gas motor just as an emergency backup. Believe it or not it has saved our butts on several occations. I always carry at least 50 miles of fuel (a 1 gallon gas can) plus a full tank.
My motor weighs 20 lbs, and I always mount it to the boat just in case of trouble, but seldom actually use it.