I bought my Boxer "Cody" from Judy Jury at Trimanor Kennels in London Ontario, back in 1994.
http://www.trimanor.com/welcome.html
We had to put Cody down last September, but after 12 years, we can say he had a great life.
When we decide to get another dog, I will almost definately try to get another Boxer from Judy. Her dogs have great temperment, and are bred and raised in a great loving environment. Have a look through her website for some mroe information, she has been in the Boxer breeding business for over 25 years, and to my knowledge has never been a "mass-breeder" like some of the other ones you might find.
I am not too sure if she has any pups available at the moment, but her site does show a litter was born in December of last year.
Regards,