Your best bet would be frontpoint security.They're not as expensive as other companies like ADT and they use ge wireless devices and mobile apps for the iphone on all their standard packages. They don't charge for installation either and they got some really good reviews. Here is their link if you want to see it yourself http://secure.frontpointsecurity.com...QQ-4664XD.html
or you can call 1-866-363-2035. I assure you they have a very good costumer service and will answer your questions. I've been using Frontpoint for sometime now and i highly recommend it to anyone.
Hope this helps!