I know wright has what they call large and small frame standers. pretty sure the deck sizes are all the same ''frame'' just different engines, hydros, wheels/tires depending on what model you're getting. not sure if scag or anyone else does the same.
if you're only planning on residential i'd say 48'' as that would be more maneuverable yet and you may find that you can get places a 52 can't. it's only a difference of 4'' and on residentials you aren't gonna notice it much. realistically it's maybe only a pass or two on most residentials, maybe less. only you can tell really, you know what your yards look like