You might want to check into a Verizon pre-paid. I've had Trac phones and ran into a lot of dead areas where the phone was useless. Someone told me that Straight Talk used Verizon towers, so I tried one of them, but even with that one I would run into places where I couldn't get or send a call (if the wife was with me, she'd use her regular Verizon phone and had no problems, so I dropped them.
Finally went with the $12.88 pre-paid Verizon version, it works anywhere that has Verizon service, and they do have the biggest coverage area. I buy my minutes online, $30 gets me three months and since I don't use the phone much at all, I never run out of minutes, I run out of time, but I have a phone if I need it for $10 a month.
They charge .99 per day that you use the phone, talking is .10 per minute, but if you're talking to another Verizon customer, the talking is free, but they still deduct the .99 on the first call of the day.