I would strongly suggest that you look into the new star on the horizon: The Cisco Adaptive Security Appliance, alsno know as ASA.
It is a firewall comparable to a Pix, has lot's of VPN options like VPN Client Access, Lan-2-Lan VPN's, SSL WebVPN, Clientless VPN. It even has the option for modules for anti-virus, anti-spam and protocol protection!
More information about the ASA can be found on the following page:
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...