Ideal setup for remote office VPN? That is a tough question to provide suggestions for, especially without knowing any requirements or constraints. The more information you can provide, the more likely someone will be able to provide meaningful feedback.
You say the remote office is "experiencing issues?" What kinds of issues? It seems the issues are related to transferring data, how much data and how are you trying to transfer it? For example, are you using Windows Explorer to copy ZIP files over the network to a remote file share and the transfers get interrupted after 20 minutes?
You say an increase in internet speed didn't help, what was the old speed and what is the new? If you are talking about a rural office where they went from 2 T1 lines to 3 T1 lines, that isn't much of an increase when talking about transferring geospatial files.
