Create a website service for automatic sending of SMS to customers

Interested in creating a site, the main function of which will be sending SMS to customers on certain predetermined templates. The mailing will go through the client database (1 database), customers will need to be entered manually. Clients are divided into 5-7 types. Each type of customer receives its personal newsletter from the general database (2 database), the information is entered manually. It is also necessary that new customers automatically receive an account on the site, for a period of up to 15 days and receive a login and password in SMS.
SMS mailing via SMS48.Sphere of rent apartments.

I answer the questions, I will complete the description.