These buildings, designed for the reception of the customers, will display all the available services (accessories, documents, food, puppies for sale etc.); thus, the customers won't have to go through all the installations (risks of barking and dissemination of germs).
This will be to your advantage if they are pleasant, attractive and commercial, with respect to the principle of openness. A picture window will allow the customers to observe the pups for sale before they are authorized to handle them.
The commercial activities (boarding, training, grooming...), though they may improve your daily income, are however likely to introduce into your exploitation a quantity of germs proportional to the customers flow. For this reason, it is preferable to carry on these activities in premises completely separated from the breeding facility and, if you have enough manpower, with different employees.