Usually not a phone issue. A plan issue.
For example this sort of thing is used to send a lot of texts or a few texts. It's a two item hurdle. The plan, then a phone. One isn't good without the other.
I'm guessing here you are trying to duplicate something. http://www.talariax.com/ and it's ilk are out there are at the CTIA show ATT would SMS thousands for lunch money. I can't guess what scale you are reaching for, or if you are just looking for the usual M2M idea.