Why dont you do this, eliminate the unlimited text messages plan and get the data plan (i am not mistaken is the same price), and if you need to send a text to anyone doit through email, every carrier has and email format for example sprint if you send and email to 10digitnumber
@messaging.sprintpcs.com or
10digitnumber@pm.sprint.com the other person gets it as a text message or verizon 10digitnumber
@vtext.com and if you google search you'll find for all the carriers, is probably easier than going through all that trouble with the sms...