While you might find a router review that gives it great range, YOUR LOCATION can cause it to have far shorter range.
And if you wonder why most routers have about the same range the reason is very simple. The power output is limited by law.
100 Feet and being reliable is going to be a problem. Not only is the distance an issue but setup is VERY IMPORTANT.
If I was to do this the router would have LINE OF SIGHT to the other building and I would put a BRIDGE in that building's window and then off to a second wifi WAP to give good coverage there.
Setup is not that hard.
My wireless network is set up in the center of my house. I would like to be able to work in my garage which is in a separate building (through thick walls) about 100 feet from my router. I have an old Linksys router now which allows for a weak connection.