Review of the JEN (Just Engines) is that the porting matches the OS .32 SX. I have one at the house that belongs to a freind and it is an atractive engine with a strikingly similar casting to that of an OS.

Of what you listed, I would go with the Thunder Tiger. If you wanted to put an OS 35 AX in that cub, you could swing a big scale looking prop, up to 12 inches after break in.