First, welcome to OCC ........
In my personal opinion ---------
I would fix the 1864 over any of the "5 yr planned obsolescence" of the new stuff out there today. $1000 a year for 5 yrs, then time for another new one.
Yes, there are many places to buy Cub Cadet Parts. That would not be an issue.
However, it is your time, your money, and your call.