Good tires for that size rim will be a little hard to come by.
You won't have much of a selection no matter where you shop at. Any tire you find from 27 by 1 to 27 by one and a quarter should seat up just fine. Go to the bike shop of your choice and they should be able to order a pair up for you. Michelin should still make tires that size and so should Hutchinson and Kenda.
Good luck.
