I'm not quite sure yet whether its 1100 or 1130, so I'll come back and update the info soon, and I don't think they gonna give me a controller for APs.
http://farm6.static.flickr.com/5134/5418245939_9997c40dce_d.jpg
This is the network that I have thought. Haproxy for distribution the load to webservers (share session with memcached and content with NFS) and 1 gateway for DNS, DHCP and Proxy. However, I'm not quite sure with the spec that I needed for the gateway (Zentyal).
I have no real experience in these things, this is the first time.