I found the Clarionet site, but couldn't find any pricing. As I recall it used to be very expensive over 700$US.
My clients for the most part are small non-profit org. I have looked at the opensource alternatives.
Also, terminal services with MSFT may be a solution. I've got a copy of the W2003 server, which I use for web sites. It includes the terminal server, and XP as I recall has the client built in.
Anyway, I appreciate your response and look forward to reading any other suggestions.