The big question is this: Can you set up the antennas so that nothing obstructs their line of site?
If you can, get a pair of nice directional antennas, and a pair of bridging devices.
matching antenna and bridging devices will cut down on "equipment issues"
Also, have you looked into a 3G/4G device from Clear? They have a home tower that turns the 3g/4g signal into ethernet.... price is a tad higher than dsl or cable but alot easier than what you are about to do... and you can get a bundled package with a USB device to carry with your laptop if you have one of those