Bob,
First, if your a newbie, Dump the router(s). It will cause headaches for you especially if you are trying to establish any VPN's. Your SME box is an excellent gateway(router)/firewall by itself and will provide all the services you need.
Second, are you trying to connect the 2 SME boxes thru a VPN or are you trying to connect to the SME boxes outside of the network?
If you are trying to connect the 2 SME boxes then there is a great contrib for just that reason.
If you are trying to connect a client behind one SME box to another SME box over the internet, then a VPN should work thru the first SME box to the second one, it just needs to be set up properly.