Probably the largest carrier with a fairly inexpensive unlimited plan, coverage-wise, is Dobson CellularOne. They're a GSM carrier and they're in my area. But all their plans require a contract, so I'm counted out.
On the phone front, however, you get your pick of inexpensive, or relatively so, phones, from the Nokia 1100 to the Nokia 6030 (for free) to the KRZR (for a jaw-dropping $200). And there are phones in between, including both the regular Razr and the v3i.
For rate plans, you have two choices: a local (statewide in my case...and I live in Texas) plan for $55 ($50 for your second line), or a $100 a month national plan (there has gotta be some sort of restrictions on that...)
On those plans long distance is included, but stuff like text messaging, web and picture messaging aren't. But hey, it's stae-wide or (if you're willing to pay) national, so if you're in their coverage area and talk 900 or more minutes a month this one'll beat out Verizon et al.