I believe 27" studded tires are hard to find. Most sell 26", 20" and 700's.
If you can't find 27's...maybe a used cheap used Mtn. bike outfitted with
26's just to see how you like it?
If you enjoy winter riding and want good tires, try
http://www.peterwhitecycles.com/studdedtires.asp
I bought Schwalbes from him with carbide studs and like
them a lot. A month and a half of commuting and no noticable
wear on the tires or studs yet.
Happy Trails
