There are quite a few breeders of Standard games around. Cackle does have a good variety of them available. Be careful that what you buy actually fit the "standard of perfection" for the breed you choose. Typically hatchery birds fall a little short one way or another. Most standard gemes breeds here in the US. fall more into the American Games category and have the wrong leg color to go with the body color in terms of the APA standard for OEG. Not to mention the differences in conformation.
Maybe some others will chime in and give you some info on finding Standard OEG shows. I have not seen any good turn outs in the last few years at shows. Usually a lot of Bantam's and Modern Game.
I actually seen more standard oriental game breeds at shows than OEG. Have you ever considered Asil or Shamo's?
Good luck in your search.
you have to keep the roosters seperated. at 6 months of age they want to fight. tie cords are the best method of containment. gives them plenty of exercise, yet keeps them seperated. the bantams will live together in peaceful harmony.