Rick,

I am flying mine with a GMS 1.20 which weighs Approx. 30 Oz. add a Bisson at about 6 Oz. and a Dubro motor mount at another 6 Oz. and you have about 42 Oz. The plane weighs just a tad over 12 Lb. this way. It is a very goes where you point it plane. As long as you don't let the nose get too high and the plane too slow with no power on you should not have any trouble landing it. Do not exceed the manufacturers recommendations for elevator throw on low rate until you are used to flying it. With the nose and tail moments of this plane I guess I would have to add about a half Oz. to the tail for every Oz. added on the nose above the above mentioned 42 Oz. So at 42 Oz. the Moki adds 12 Oz. to the nose and would require another 6 Oz. in the tail which would make it a 13+ Lb. airplane with the wing loading getting a little on the high side. My battery is right behind the wing and you might be able to put yours in the tail for a little weight savings.
I also have a brand new ST 2300 and the thought has crossed my mind about installing it in the G202. After not quite a gallon of fuel it is turning an APC 17-6 at around 9600 RPM where the GMS turns the same prop at about 9000 RPM. I really like the way it handles, one back flip starts every time and no dead sticks on my Stinger 120. It does weigh about 8 Oz. more than the GMS. If I were in your position I would be tempted to mount the ST and fly the plane, then later if I wanted more power I would substitute the Moki. Anyway, good luck whichever way you go [8D][8D]..............RJ