I purchased an old 70's/80's steel lugged bike that I want to convert to a single speed/fixed-gear. It has steel 27 inch wheels. I'm considering purchasing a new rear FG/SS flip-flop hubed 27 inch wheel for the conversion. This would allow me to continue to use the same 27 inch front wheel. Also, I could continue to use the same brakes and not need to adjust reach or buy new brakes.

My only concern is that 27 inch wheels are uncommon as compared to 700c. Is it a mistake to invest $80 in a new 27 inch wheel since 700c is more common?