You are rather optimistic about mobile internet in US. I live in San Jose, there is areas in it without mobile coverage. I live well within city limits and have femtocell at home in order to be able to talk and sms (at&t). If you go outside of metropolitan areas you are likely to loose signal quick. When I was driving to LA a while ago, the only way that I could have signal 80-90% of time was to have two phones - one from AT&T and one from Verizon.

Anyway, check your linkedin. I pinged (i think) you there. I may have a few practical suggestions that are better discussed offline.