I have a 2.3 hp Honda mounted on my TI, the motor is very small and lightweight (27 lbs). I used to have an Island Hopper 2hp 4 stroke, that served me for several years as my emergency backup motor. With my Hybrid tri-power setup I only need to run the motor at 1/4 or less throttle and it provides more than enough power for my needs so it is very fuel efficient (about 100 mpg), the rest of the power is from the pedal drives, and the sails (tri-power).
My motor mount is just PVC tubing stuck into the rod holder holes creating an A frame with two 3/8 steel rods through the pvc. A 2x4 piece of wood is the motor mount with two 7/16 dia holes drilled, then the steel rods epoxied into the board. I also filled the PVC in the high stress areas with epoxy to make them stronger. I built that motor mount 4 yrs ago and it is still going strong, but the 3/8 steel rods are all rusty ( I should have used stainless).
This setup works fine on a TI, and the motor is in a nice position, I have no idea if that same location (mounting using the rod holders) would be convenient for an AI.
Here is a link to Island hopper, they make a rod holder motor mount (http://www.islandhopperoutboards.com/ka ... ount1.html
Hopefully this gives you some ideas. I think there are tons of posts on here with all kinds of motor mount ideas if you search around.
I've been running outboards on my TI now for 4 yrs, I go out every weekend in pretty much all conditions and have never swamped a motor.
Typically when I have the motor tilted up, I throw a cloth bag (like a tote bag or a grocery bag) over the motor head to keep it from getting too water logged from the splashes. When in rough seas (4 ft or more breakers) they both have lived thru occasional dunkings as the waves pass over the entire boat (as long as it's just a wave going over, with the motor not running and covered with the bag).
I had the island hopper on both our Oasis, and our revo's a few times, just messing about, as long as you don't tip over you should be fine. However without AMA's you need to counter balance the motor, and the setup is a little shaky (easy to tip over) If running on an adventure kayak, I would either keep one AMA on, or add Hobie sidekick AMA's just in case when using the motor (it's just too shaky without)
I find that tilting the motor slightly so the prop is almost under the boat gives you the best steering using the main rudder on the boat. If the main rudder breaks you can still steer with the motor tiller, but I normally keep the motor tiller locked.
One other point is if you plan to use the motor for powersailing or tri-power, changing to a higher pitch prop helps, because pretty much all the small motors have very low pitch props (typically about 4"-5" inch pitch, basically designed to propel much heavier boats) will only get you to 4 mph max speed. Going to a higher pitch prop (6" to 8" pitch) allows the kayak to go much faster with sail and pedal assist.
Hope this helps