Need help to set up VPN with SBS 2003 and Linksys WRT160N

I have searched constantly for over a week and read everything I can get my hands on, but still can't establish a VPN between my SBS 2003 on a PowerEdge T105, through my Linksys WRT160N router which states it supports VPN passthrough, and to my Dell Precision M2300 laptop when out of the office.

In a nutshell, I have the following configuration:

DSL modem>Linksys WRT160N router>PowerEdge T105 with SBS 2003. 

I have wireless clients accessing the server and internet via the wireless Linksys router in the same office as the router.  I am accessing the internet and server via a wired connection to the Linksys router as long as my Dell laptop is in the docking station.  I travel frequently and need to access the files on the server when out of the office.  I have set the Linksys router to enable VPN passthrough through PPTP, IPSec, and L2TP.  I have enabled port forwarding for Telnet and FTP to the server's IP address.

I thought I was getting close with a guide from the Microsoft website, but when I got to the section telling me to configure both VPN access and NAT, my server stopped me with a message that less than two network interfaces were detected.

What I really need is a step-by-step guide to the correct setup for my server, router and computer to establish the VPN.

If you can even direct me to a link of an existing guide, it will be greatly appreciated!