I want to purchase a new system comprised of 19 APs across a WAN consisting of 5 locations. I have a couple of questions. Is there any advantage of going with the 5500 series controller over the 4400 series? I want b, g and n coverage. Other than that, I need basic wireless and possibly a mobile phone or three. We are in existing Cisco networks with 3560 PoE switches in place and have a Cisco VOIP phone system. Traffic and number of users is expected to be light. We also have 2800 routers at each location.This will be in a government facility with high security standards also.