Adding '.com' is a good idea but I would add it to the end of the 'SIOUX' in small letters. What about changing the feathers to mimic the feathers our logo has, including the colors? Would just using the feathers infringe on the copyright?
A graduating (Navajo) high school senior (tomorrow) is working on a logo for me. Because of finals and graduation, it will take her a little while to get it done. She's an amazing artist and is really excited about coming up with a good 'SIOUXSPORTS.com' logo. Hopefully, she will also know how to post it as I have no idea how to do it.