2 apache servers via apt-get?

You can run two instances of the same apache binary with different configurations. Something like:

cp -a /etc/apache2 /etc/apache2-secondary

Set up the configuration in the apache2-secondary directory, then fire off something like:

httpd -f /etc/apache2-secondary/apache2.conf -k start

Unless there is some specific Apache 2.2 feature you need in the proxy layer, you could also use lighttpd as the proxy.

Nothing specific to Apache2, it's just that I need the ProxyPass functionality for the front-end and am very familiar with Apache2 config but have never used lighttpd. Might have a go though. Is lighttpd easy to set-up for 6.06 using apt-get? And can it do proxypass (or equivalent)?

And thanks Xan, that looks like an easy one to try for starters.

Lighttpd should be able to do what you need; the doc for the proxy module is at http://trac.lighttpd.net/trac/wiki/Docs%3AModProxy. In Debian, lighttpd is just an apt-get away; don't know about Ubuntu.

OTOH, just running two instances of apache with different config files might be more convenient. The advantage (to my experience) of lighttpd is less memory use.