Coors always comes in the kegs with the spare tires that make them not fit in small fridges. As far as the 1/6th bbl kegs, they should be easy enough to find, if not, ask the place you're getting kegs from to order them.
Jason Harris, Beer Dork Extraordinaire and wannabe blogger
Homebrew noob, moving right along
In The Pipeline:
Empire Strikes Brau, Dead By Dawn, Fail Ale, Yellow Fever Blonde