Been there... done that. One of the biggest Q's when deciding what type of equipment to purchase is; The remote office that has the 3-4 pc's, will this office have a printer and will the other office need to be able to print to the office with the 3 - 4 pc's. If you say yes, then you absolutely need VPN routers at both ends, if not, you COULD get away with using a 1700 series router. However, if you wanted to VPN from home you could use the IRE SafeNet client with IOS 12.1(1)T, 12.1(2)E, 12.1(2). ADSL is OK, fractional T1 much better and cable is great for home use.