Custom collars: http://www.blockydogs.com/

I bought a collar from them even though I usually preferred a good leather collar. It lasted longer than my dog did. People always asked where I got it.

Dog Tags: http://www.boomerangtags.com/

I ordered pet tags for my dog and Medical Alert tags for me and some family from those guys. The quality and durability(both stainless steel and plastic) was great on both types of tags. The medical alert tags are military style dog tags. The site lists them as Mantags/ Military tags.