Thank you for the updated information, I was getting worried my question would go unanswered. To add to my original post, we purchased two LTM 3400's and will be initially setting them up as primary/secondary. My initial thoughts were to put the bigip into dmzFE, but have all the webservers in dmzBE.
dmzFE will be a small network of public to private static mappings
dmzBE will be all the iis web servers
The bigip will have connections into both networks. The web servers will use the bigip in the dmzBE as their default gateway, and the bigip will have its default gateway as the firewall in the dmzFE network.
Thoughts/Suggestions?