Site to Site VPN - Linksys and other low end routers

[stancounty]

Member vpnsecure posted a message early last year regarding configuring site to site VPN's between Linksys routers running OpenSWAN\OpenWRT and Checkpoint Gateways. Here is the link to his guide:
SOHO VPN Router Wiki : TOC

I'm curious if anyone has had any success with this, and if it's possible in NGX R60 to do the same without the need for generating your own certificates and using PSK's instead.

I've been searching high and low for something even remotely close that describes in detail how to establish site to site VPN (IPSEC) between commodity hardware such as the Linksys VPN routers, Netgear Prosafe VPN routers, etc., and Checkpoint Gateways.

Any recommendations or pointers would be greatly appreciated.

Thanks in advance...