ZTE Z431: Does it need a Text Messaging Plan for Post Paid Accounts?

This is for my post paid account.

I am planning on changing my Blackberry Torch 9810 to ZTE Z431 since I don't use much Data Plan. In fact, I have no need for it since I only needed the BB's organizer function. But I have to compromise if I don't want the BB Data Plan.

So, if I change my BB phone to ZTE Z431; am I required to get a Text Messaging Plan or a regular voice plan will do?