Been there, done that... in my case way back in the days of VFP3, and I still find VFP (now VFP8) the best front end to work with for SQL.

Anyway, to start with, use the VFP upsizing wizard to copy your database to SQL. It will move structure only or data as well, as you wish. It can also create remote views of your new SQL tables that can be used as a direct replacement for the local VFP tables. The VFP engine can handle all the concurrency, caching etc for you if you wish.

In our situation we access the backend data via remote views for data retrieval, but send all writes back via SQL pass through code to get even more control over the process and to limit the amount of client code that executes during transactions.

Good luck!