I've got a O.S .40 in mine, personally I wouldn't go lower than that. Although the minimum is .35 I was told it is always best to at least get the size in the middle range of the recommended scale, but if you must use the .35 it certainly can - but the power will be that much more limited.

Sig Kadet Senior trainer http://www2.towerhobbies.com/cgi-bin...?&I=LXFF89&P=7 would be a perfect candidate for your O.S .35 and a real great build if you don't mind building your plane.