It really depends on your area. Verizon and Sprint have the same kind of cell network. ATT and T Mobile have the same kind.
But really talk to those you live by and who they have and how there cell reception is. I assume thats what is important, not what kind of phone to get.
For choosing your cell phone carrier,Go to a phone shop in town, tell them what you want, they can advise.Before getting your cell phone service provider,Make sure your phone is unlocked and accept that carrier,If it's restricted by other network carrier means,You will need to unlock your phone.For unlocking you can approach your current network provider or else try to buy an unlocking service from any one of the online unlocking service provider like MobileUnlockSolutions.com I hope it will be very useful to you.