Hi,
I currently run 3 aircraft with rotax 912's in various guises. I have the 100 hp version in my mto sport gyro which gives bundles of power and fairly good fuel consumption. Some of my friends run the 914 and I have to say the turbo is not good. I think it's an old garret they have bolted on. If I was in your position I would look at the 100 hp and forget about any add on turbo kits. KISS - keep it simple stupid. On another note they are superb engines all be it expensive to buy, well certainly in the Uk.