If you have ArcGIS 10.1 you might think about using ArcGIS Online (AGOL) to share web content within your office and out to your satellite offices. ESRI could host the mapservices where you would just need to provide them the data.
I also think they could host simple template type applications where they would use the services with your specific content which could be combined with their base maps.
You would be limited by their out-of-the-box tools, which might be good enough anyhow. If the out-of-the-box tools do not meet your business needs, they you would need to perform custom coding which could be done in various languages (VB.NET, C#, Javascript, etc. to name a few).
I would suggest viewing their documentation on AGOL as a start.