Hello! By customer you mean also de Owner of the estate?
If so, then yes, with a related field through the connection you made with the many2one. you could. 

in general, as long as you have a many2many or many2one field, you should theoretically be able to "grab" any field from the model you are connecting to through a related field or many2many one. 

if the customer is not the owner by itself, but there is some relation between owner and customer, you could use the original many2many as uid to search the customers of him and asing one of them here (using domains). 
it is a bit complex if you never tested Studio before or have no background on programming. but it is doable