firewall + ipsec?

[Neal D. Becker]

I need a firewall that will work with ipsec.  It needs to pass protocols 50 + 
51.   I don't want to write all the rules by hand, I'd like to find a 
reasonable firewall setup script that I could just add a couple of lines to.  
Actually, a gui would be great.

I have tried:

redhat-config-securitylevel
firestarter
shorewall

None seemed to do the job.  Several could open ports, but only for tcp and 
udp, whereas I need other protocols (50 and 51).

Any suggestions?