Linksys to Linksys vpn connection

I would like to know if it’s possible to connect to site with two linksys router.

Site one :
A. Siemens speedstream 6250 (for Internet connection with a fixe IP address)
B. Linksys WRT54G (for LAN & Firewall)
C. Small Business Server 2003

Site two :
A. Siemens Speedstream 6250 (for Internet connection WITHOUT fixe IP Address)
B. Linksys WRT54G (principally use for WIFI)
C. No servers, only workstations.

I would like site number two able to connect to server at site number one….

Thanks for your help