Trying to buy a 500k commercial property

[George Adams]

hello,

I am trying to buy a 500k office building for my son .

He has  consoling practice .

I have a 800+ credit score, 

own 2 propertys fully paid off  for around 15 years .

(worth 250k-300k each ) 

Not to much debt 

My question is about a funding :

Do I go with  a commercial broker, or a small local bank, a mortgage company, or a big bank 

Thx for any help  !