What are all the possible AT&T Internet/texting plans you can have?

If I were to buy 1 iPhone 5s 16Gb on a new plan and want unlimited internet & texting but limited calling, about how much would that cost a month?

AT&T doesn't offer unlimited Internet anymore, but they have the share everything data plan which runs about $120/month with 4GB of Internet. If you are wanting to go on an individual plan with a certain amount of calling and data, you can still go on Amazon Wireless and choose the individual plan.