Has Kubota stopped offering a flailmower option?
The larger issue is your tractors three point hitch lifting capacity
There are many European brands that are compatable with your BX25.
ANy 4 foot cut flailmower will be more than adequate for your BX25 as it has 17.7 horsepower
at the power take off.
You can special order a Caroni 4 footer through agrisupply if desired and it will
arrive in 6-8 weeks depending on when the agrisupply folks have placed an
order with Caroni in Italy.