relating servers in different farm?

[Wayne <wayne@xxxxxxxxxxxxxxx>]

In the process of setting up NAT load balancing,
is there a easy way to relating server in both port 80 and
port 443? 

Say I have two farms, each with same three servers.
One farm load balancing HTTP requests and another
farm load balancing HTTPS farms.  To make sure the
user in the persistent mode connected to the HTTP
server always go to the same server for HTTPS service,
we would like to have some way to relate the services
between the two farms, is there a easy way to do it? 

If not, what else can we do?  Thanks so much!