ReBiCycling ..find an old steel 80s bike that fits.. with horizontal dropouts,
and build or buy a rear wheel
single speed freewheel you can just re dish the rear of a common freewheel hub.
I've done that with a 5 speed wheel.

It would be way less than buying new .. won't matter if the locking it up every day chips paint.

want to do the fixie thing ,
then you start with a wheelbuild around a flip flop hub
lockring on one end for track cog. freewheel on the other.