Any Widebodied a/c on the FCA2300 going to RHO on the 22nd of august returning on FCA2301 from RHO to Man on the 29th August

Very much doubt you would get to travel on a 767 to RHO, although it has been known to get a widebodied a/c on some short-haul flights, but this is only because they have to use any new long-haul a/c on short-haul routes for a time, before being able to use them properly.

Like LeeMan8 says, expect either an A320 or a B757.

Does FCA have any A321’s based at MAN at all? I know they have some within their fleet (not exactly sure how many), but I think one is currently based at LGW!