Reverse proxy and load balancing with PFsense

[pfsenses]

Hi,
I have a virtual PFSense server which I'm trying to set up as a reverse proxy (using vanity) and load balancer.
I have a router which provides a basic firewall for my home network, a ESXi 5 server and NAS provide a virtual environment which hosts my web and utility servers.

Most of my websites are virtual hosts on a single virtual server, however I have a site which has two front ends which i'd like to load balance.
My "home" network uses a 192.168.20.0/24 range while my "server" network uses 172.16.100.0/24
From the ESXi side, the "server" network is just a isolated network which is bridged by my PFsense firewall.

I've set up three virtual interfaces for my PFsense server, two WAN (facing my home network on the 192.168.20.x range) and one on the "business" network using the IP 172.16.100.254.
I'm trying to use one of the "WAN" interfaces as a management port to access the web UI and the other to forward web traffic either via reverse proxy or load balance.

My home router forwards ports 80 and 443 to the firewall's WAN port set up for web traffic.
I managed at one point to set up forwarding so one of my web servers was accessible on the web traffic port of the PFsense server however now the best I get is "Potential DNS Rebind attack detected".

I think i've tried to do too much at once and gotten myself a bit lost, so i'd appreciate if someone could walk me through setting up the PFsense box one step at a time. I'll run the server from iso and test the config (or just snapshot it)

Thanks in advance for any help you can provide.