Do you have the B2650 now?
Buying a tractor and mower that you know will have to cut only a 30" swathe width does not make sense to me. Maybe ......for one acre, but for more than one acre buy a tractor with at least 33-horsepower.
The 'Bs' are a little tippy. I owned one which I mowed with. There may be surprises lurking within that TALL grass.
BUY ENOUGH TRACTOR!