I need to develop an app that will be accessible to approx. 6 offices located across North America that are connected via WAN.

The one possibility I've started to investigate is using SQLServer 7 as the backend, having SQLServer in each office and using SQLServer's Merge Replication technology to update each offices server nightly. Also, the merge replication technology in SQL 7 will work with workstations (i.e. notebooks for offline users, sales, etc).

The ROI on this shouldn't be a major issue because future apps have already been identified that will have the same WAN user access requirements.

Looking for opinions on this and alternatives others have implimented. I've already tried running the app over Citrix and the remote users weren't very happy with the results.