I made three different versions for different purposes
1. The main profile images
These were custom made by placing my username underneath the symbols for AT&T and CBS with matching colors for the username text
2. The signature
I use this whenever a signature is required on a page and I used the AT&T symbol again, but to make it look more like a signature, used a horizontal layout with the username next to the AT&T symbol (with the username being a matching color as well).