I Need help finding the right cell phone and plan (Read Desc)?

I am 17 years old and my parents are making me pay for my own cell phone and monthly bills. I want a cellphone. I need the bill to be as low as possible, as I am on a tight budget at only 17. The phone can be any kind whatsoever, though i would prefer one with a full keyboard. I need a plan that is cheap, i don't really need any minutes, but i want unlimited text. Any carrier will be fine. Please help! Let me know what phone and plan.