I've got both (enom and godaddy) as partner though I recommend that you go for ENOM for complete private label as treated as your own domain name registration.
The wildwestdomains.com (godaddy) provide private label service though some text, you will see wildwestdomains unlike enom. The advantage of wildwest is they provide hosting and email services as part of resellership.
check this site: www.domainresell.biz , they'll give you a no setup fee account with prices starts at $8.69. I found other sites that offer fee accounts that starts with $7.99, but i haven't signed up with them though, and also, i don't know if they could provide you with a prompt service.