If you can, talk with local 4-H poultry leaders. They may be able to direct you to good breeders. Don't get birds from a hatchery if you're going to be showing, however.
You can also check out some of these websites to locate breeders online:
http://www.poultryshowcentral.com/Chickens.html...
The problem I see with Old English Game bantams is that if you want to show cocks (roosters), you have to dub them. This may prove daunting for a new, young poultry owner. True, you can just show the females or only cockerels, but if you ever want to show mature males they'll need to be dubbed...
Another nice small breed is the Dutch Bantam. They usually have excellent temperaments (even the roosters), are very inquisitive and sweet birds, lay a decent number of small white eggs, make very good showmanship birds, and weigh just a couple ounces more than Seramas.
I would recommend Wyandottes Bantams or Bantam Plymouth Rocks. Cochins and Silkies have nice temperaments, but you will sometimes have trouble keeping them clean/fluffy enough for showing. Those fluffier breeds can also be more susceptible to mite infestations. Wyandotte Bantams and Bantam Rocks...