The main "problems to avoid" are networks that don't have good coverage in your area. Stay away from PCS networks like Sprint and T-Mobile that have coverage only in major cities and along some freeways. Along with that, make sure you get a phone that has 1G digital capability (CDMA or TDMA) - nearly everywhere has 2G now, but it never hurts.

Verizon has the best reputation among the long-distance motorcycling set. Unfortunately my own traveling has really been curtailed since I switched to Verizon, but "out east" anyway I've never been more than a few miles without coverage. Southern Indiana is similar to southern Ohio - rural hill country - so there are always going to be pockets in the shadows of hills where you have no signal (are you sure that there's coverage at your homesite at all?).

You might get the best deal by bundling services. Have you checked with the company that will have the landline, TV and internet at your new homesite? Even though you'll only be signing up for the wireless at this time, some companies will let you bring an existing contract into a bundled plan when the time comes (check first, though).