Comment Here's your plan (Score 4, Informative) 239
I work for a small, rural ISP with many of the same challenges that you're looking at. We started up as a dialup provider in 1997 and have moved into wireless and DSL.
First, get some money. A lot. Shitloads. Second, raise your pain threshold. Third, that whole "this will not be my day job" thing? Forget that, it will be your day job, night job, weekend job and holiday job. Finally, hire some talent that isn't lost in licensed frequencies and other issues.
What we do is wifi mesh. We use grain elevators, radio towers, old TV masts at customers locations, whatever we can ad AP or radio on to help extend the mesh. We use inexpensive customer premise gear, lightning sucks around here. You'll need some backend equipment, bandwidth backhauls and some routing gear; everything we use is open-source, DYI equipment because money, that's why. Don't try to cover the entire area at once, hit customers you can easily reach, solidify them and then move slowly. DO NOT! run an ad that there's a new ISP in town offering high-speed service, you likely won't be able to meet the demand.
A guy, you, can totally do this. But you're going to need some help, some money, and some adjusted expectations. If you're a gambler, go for it, if you're hoping to make a bit of money from it on the side, get out now and save yourself.