For a 52fs i'd start with about an 10.5x7 or 11x7, one problem with 4s is they typicaly like to swing a larger which can be a problem with ground clearance on some models.

as for fuel 4s typicaly run about 2% less oil than 2s you don't HAVE to youcan run it on 2s fuel but 4s dont need as much oil.