I just used the Rover from http://www.equitainer.com/Canine/
Shipped two boxes directly to the stud owner and ended up using both of mine and one of hers to do three inseminations. Had a litter of 9 healthy labradors two weeks ago. Boxes are sturdy and the precious "gold" arrived in perfect condition.
I thought about those insulin boxes my husband gets. I had 12!! Just tossed them all. Next time maybe I'll bring them to a show and see if anyone wants them--you're right...brand new, sturdy and with an ice pack.
I've used CLONE chilled semen kits for years and have had great success. They sell from http://innovativecaninereproduction.com/html/chilled_semen.php There frozen semen is amazing too. I hear they are under new ownership too! I tried minitube once and was very unhappy with the results. I wont make that mistake again.