SQL Server 2000 With SQL Server Express 2005

I'm an engineer in a manufacturing environment. We have a centralized MS SQL Server 2000 running at each location of my company. I'm developing applications that will run on "Test stand" PCs, where product is tested. Current software works solely with csv files for data output and works independently of the network. To limit the reliance on the network, I'd like to setup small workgroups, or cells, of test stand PCs that communicate with a MS SQL Server Express 2005 that is replicated with the facility-side server databases running SQL Server 2000.

Will there be any compatibility issues replicating between these two? Obviously, the SQL Server 2000 will act as the publisher. Note that our IS department will likely not go for 2005 for awhile and I have no input to get them to move to this. It will be a little bit of a dogfight to get their support on the "cell" idea I'm considering. Our faciities in Juarez have frequent internal network issues, so to maintain production, it is very important to be able to continue testing product when the main network is down.

Thanks in advance for any insight.