First of all seems to me that your data transfer requirements are very focused and specialized and a full-fledged VPN solution might not be necessary. Remember that VPN's are really used for network or application security. If it is indeed a data transfer application that is needed some quite robust encryption technologies based on public/private key cryptography might be appropriate. For example, SSL and SSH are two that come to mind.
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.