The excelleron (as far as I know) will be a bit heavier RTF than the widebody. Alot of guys are flying the WB on YS110's, so I don't think your OS120 is a real stretch...however, it may be heavier than the YS, so be prepared to mount an aft rudder servo or something similar to prevent adding tail weight...

I have seen the OS120 on a GSP Swallow and it flew quite well but really labored through the intermediate sequence.....o.k. for the Sportsman though....