If you are looking for a world of pain and challenge with failure being the most likely option then go for it. Haveing the GVP will help you get there quicker.
Once you have a tcpip stack with a gateway defined you will be able to FTP and HTTP(Browse) to the internet using your adsl. As long as you can fit everything in 10Mb.
A network card might be a challenge though..Thus the tutorial use of serial and a modem..
Good luck...!
