Twilio or other SMS Platform Expert Needed

We are looking for an expert who can build the following system & guide us all the way through in deploying the system. The system would be such , We would use it for our promotion. A phone number ( Toll free is possible) is displayed on our premises. When any interested person calls that number they get registered in the database & the call gets disconnected. Now we can send promotional sms to the user from a web admin. We'll use a SMS provider for this. We prefer twilio but suggestion would warmly welcomed. We need basic features from web admin for which a list would be provided to selected user.