The best way is to visit one or two of the large poultry shows to see what takes your fancy, literally!
There are some good autumns shows around and the 2 best ones are the National Poultry Show in November run by the Poultry Club of GB and the Federation of Poultry Clubs in December. At these two shows you will find around 6,000 - 7,000 birds. Each breed will have a stand with representatives of their club on hand to give information about their breeds and importantly the standard and how to access local breeders/stock. Some breeds are better than others for exhibition and they will be able to advise on the the pros and cons of their own particular breeds.
I breed faverolles and brahmas, lovely birds for showing, can highly recommend them but I am terribly biased!
http://www.poultryclub.org/
http://www.fancyfowl.com/
couple of links one to the PCGB and to the fancy fowl which is the mainstay magazine for the fancy, with details of all the up coming shows and poultry events..
There are links on our website with information or most of the breeds and events/exhibition calender.
http://poultrykeeper.com/chicken-breeds
http://poultrykeeper.com/poultry-shows-and-auctions-calendar
Good luck and let us know please what breed you choose!