When I contacted Sheldonbrown, several months ago, about going up from a 5spd to a 6 or 7spd, they had at that time a set of 27 x 1 1/4" wheels selling arount $99. You can try going into a bike shop near you and see if they might have 27" wheels.

One by me had 1 27" front wheel, and about 6 700c wheels, they said they could special order most any part and have it there the next day. Maybe your bike shop can do the same.