Does the 227 use a vertical bobbin? I checked ISMACS and Singerco for a manual and got nowhere.
If the 227 is a class 15 bobbin I would go with it. It's in nice shape and I don't think it's a common machine compared to other Singers. At least I don't think I've seen many.
The 15 is a great machine and they do FMQ quite well. If the 227 has a vertical bobbin it should be good for FMQ too. If it uses a drop in bobbin I would go with the 15-91.
My indecisive answer,
Rodney