I suggest going with three AC110's and call it a day. They should easily handle occupants of a 125.
I have run 125s all three ways, FX only, FX AC combo and AC only. The time it takes to clean a single FX you can clean all three AC's.
If you must go with a cannister I suggest a FX series. Ease of use, quality made, availability of parts. Drawback is all cannisters are a PITA to clean.