after having a quick look around i have not seen any Kubota ( or similar ) tractors with front end loaders  between 25-55ph. ideally one with an under belly mower with pto.. are they available in Thailand if so where please 

 

Ask your local  Kubota dealer , the  problem  with low hp tractors    the hydrolic  pump  is not always  man  enough  to work a loader ,the pump has to  work   2  rams ,  .the weight  of the loader   plus  what   ever you have in the loader  bucket.

Have seen  loaders  for   55 hp tractors , or even the  36 hp  tractors  are  common, and work well.

 

AS  for an under belly mower  I do not think  you will find one in Thailand  try  finding  a   Kubota catalog  with one in  and show  your local dealer, he might be able  to import one for you , odds are  he will  have never seen one  before , or import  one   your  self  .

 

If it you need a mower for just cutting  grass around the farm etc ,a Thai made grass topper would do the job, fits on the 3 point linkage, about  a   4 foot cut  topper would cost  about  18-20 000 baht.