2 LAN to be connectec in VPN

Hi,
I have VPN in mind to connect our 2 LAN , they have the ff:

LAN 1
SBS Win2k3 server (runs ERP system using SQL Server) this server is behind a router linksys router (non VPN act as a gateway with static IP)

LAN 2
Client running in Win2k and XP, one Pc here had 2 LAN cards, 1 nic connected to dsl modem (with static IP) to act as ICS, and 2nd NIC connected to hub.

Since both LAN has static IP, how do i implement VPN? LAN 2 users have to run ERP apps and have to connect to LAN1 server for SQL connectivity.