Personally I would train in the Enstrom, I've got some hours in the F28C and it is the closest thing to a larger heli you are likely to be able to train in. Doesn't have all the power in the world, but it will certainly teach you throttle correlation (Something i think R22 guys seem to disregard as worthless). I also agree with Flying Lawyer's remarks regarding the Bell 47. Best training helicopter out there and it flies so smooth. Autos are cake compared to the 300 and R22. I have most of my time spread between Bell 47s, F28Cs, and the 300CB and C models. Obviously, I may be a bit biased, but I believe learning throttle correlation should be in the initial stages (private training). If you want to fly R22s I would then get an instrument rating or commercial/cfi in one.