What are the cameras already in use by the group? It might be helpful to have the same model as is already being used. I have a Nikon FM2 as a manual focus camera, which I love

. You should be able to pick one up for around 150 quid with 50mm f/1.8. The FE series is similar, but has an electronically controlled shutter, so won't work without batteries.

Another possiblity is the Olympus OM10, but make sure you get the manual adapter, otherwise you'll only have aperture priority.