MS SQL Server - Application Architecture Issue

Thank you in advance for any advice that is provided from by the Dev Shed Users.

I'm on a development team that has been having an ongoing discussion/argument about the best way to handle our users needs while in Europe.

We are developing a Purchase Order application in VB.net using MSSQL Server 2000. We have about 5 out of 10 users that take a six-week trip to Europe. While in Europe the users will need to use the application. However, there are some cities they visit where the network connection will be slim to none.

The ongoing argument is as follows:

-Should we create a server running SQL Server 2000 for them to take Europe and sync up the two databases when they return?

-Should we create a version of the application running MS Access?

-Should we create a version of the application running MySQL?

-Should we do something completely different that we haven't thought of?

-Also, I'm not sure if the following is a possible architecture, from what I've found online I haven't seen an architecture that runs both SQL Server and Access (hope this makes sense):

Build the VB.net application running a shell of the database in Access (locally) that temporarily houses the data and tracks the database transactions made while using the system. Then upon closing the application a ?module? would execute that would perform the transactions made by the user on SQL Server. Then we could dump the SQL Server Database to an Access database before they go to Europe, and run their changes on the SQL Server Database when they return. Users at home will not be making changes to the same data as those in Europe.

Again any help would be greatly appreciated.