About to purchase used mower without deck - Question

I'm thinking about picking up a 6-7 year old Craftsman DYS 4500 26 HP Kohler engine w/150 hours for $500. The mower was originally fitted for a 54” deck. I'm not sure if I'll be able to find an exact replacement deck so I was wondering if I can fit it with other size decks? How different are decks from one craftsman to the next? Thanks for any input. Much appreciated!!!