802.11n is a wireless technology capable of transmission rates up to 300Mbps. An access point running 802.11n will allow your clients to connect to your network from where ever there is coverage.
What about distance / coverage then? I have seen some manufacturers claiming distances of around 400 feet but but it does vary from vendor to vendor. You need to be aware as well that as soon as you decide to put your access points inside a building then wall thickness and material together with overall building layout start to mess with those figures, whichever vendor you went with. You really need your building surveying to determine how many access points you need to provide coverage and where they need to be fitted.
Once you have them all in you can integrate then with an internet connection. If you want to use bonded T-1s then thats an option as long as you have them terminated on a router which can handle it.