VPN: I'm looking for sugestions

[Damir Dezeljin <programing@mbss.org>]

Hi.

I have to set-up an VPN server and an VPN client. The two location will be
connected to the internet by ADSL.

The VPN server has to support one client for now with a posibility of
aditional clients in future. The server has also to support various access
rules (e.g.: one client {LAN} need access to the entire LAN, whiles the
other client {maybe another username / key} has to have access only to the
specific port on a specific IP address).
The client has only to route an remote LAN to the VPN server's LAN and
viceversa.

Can anyone give me some hints which software to use;
What are the minimum hardware requirements (there will not be a lot of
  trafic - I'm now using an ISDN connection that satisfy our needs);
How to enforce the described access policy?
I'm looking into a relativly cheap solution with 'black boxes'
  (prefabricated ADSL routers), because they can be take up by less
  experienced administrator in the future, however I have some old
  machines that I can use to implement a Linux solution if I will decide
  to go this way. So please give me some sugestion for any suitable
  prefabricated ADSL router and how to go with Linux (which distro /
  software / ... - I'm thinking about Debian with 2.4.20 + FreeSwan).

Regards,
Dezo