Originally Posted by barbwyr
You can't assign ringtones to individual contacts for SMS. There is a work around that involves setting up profiles for each contact but it is not 100% effective and I am ready to dump it myself. In the menu of each contact is a link to set a custom ringtone for that caller. You can also go into the active profile and set a single ringtone for ALL SMS.
Here's the work around if you wanna try it. How to set custom text message tones to contacts
You CAN do custom tones for SMS, by sender. I have two set up one for my wife and another for my office, which serves as a 'pager' for callouts.