If I buy rsim 9 pro will it fully unlock my sprint iPhone 4S ios 7?

I want to know if it will give me SMS mms and 4g data for AT&T service

It might unlock it, but the MMS might not work because you need a way to access the iPhones APN settings. There might be ways to do it, you can search the sim swap method, or jailbreak your iphone and access the apn settings from there.( I don't know if there's a 7.0 jb yet)
hope this points you in the right direction.
gemcity@rocketmail.com