That i know of saito only makes 4 stroke engines (could be wrong wouldnt be the first time). I would suggest a .30 or about that size engine its not bad having na little extra power is nice. to little power is not alway fun that being said i recomaned somthing like this engine-
http://www2.towerhobbies.com/cgi-bin...&I=LXBY43&P=ML
I dont own one of these engine but from everything i have read and herd from it is an excelent engineOS has a strog reputation for rialbilty and eass of tunning
Steven