There are several reputable companies online which sell kegging systems. They range in price anywhere from a few hundred $ to outrageous. Might I suggest an alternative? If you can find empty Pepsi or like cannisters, configure your own. If you've got a brewing supply store nearby, they should be able to hook you up with all the necessary hardware. Plus, it's cheaper. The largest single expense is probably going to be a fridge, and those can be picked up used for a song, smaller ones new run less than $150.00.
The kegs I've got are 22" tall. There are lots of mini's that will accomadate these. Just measure the inside of the fridge and be sure to give yourself a couple extra inches for maneuvering the kegs. And, these "kegs" will hold a 5 gallon brew. I think I read a post somewhere (maybe in the homebrewing section) where there were empty soda cans in their area available for $15.00.