How fast is your Mac? How much RAM do you have? VPC likes lots of RAM, and especially a big cache. I don't know your situation, but you may wish to investigate using Mac-native VectorWorks at home, and transfer the files to and from the other programs.
BTW, VertiGoGo, I use VPC 2.1 w/Win95 on a beige G3 with Rogers. I provision a manual IP address connected to a LinkSys. It works fine, even connecting through a VPN to work.