There are pro's & cons setting up multiple databases. The long & short of it means more admin.
if youre customer has the discipline to maintain his stock & only create products from a single location (DB) then it can work great. Otherwise it may be better to run off 1 DB with multiple warehouses. My experience is that most customers start off with a bang & then 2-3 month later it becomes a nightmare & it is expected of us to "fix" it.
In short - here are the 2 options as I would set it up.
Option 1 Customers has 2 businesses with a system (or more) per business.
1. Set up each business as a server with it's own complete database.
2. In the office or central pc, set up 4posmaster with the 2 locations.
3. The office would be the "Master DB" where ALL new products are created & then synchronised to the individual systems.
4. You would then purchase all stock into the "Master" & do a company to company transfer.
As I've said - this takes a lot of discipline & quite a few of our customers are using this successfully - especially multiple banch stores.
Option 2 - Same configuration.
Steps 1 - 3 are same as above.
4. Simply log into each company individually to do price changes & simple admin.
5. You may sell between the companies using Debtors & set up the sales channels at cost.
Let me know if this is clear.