The Spotmatic Electro have aperture priority, IIRC, but I think it depends on the use of SMC-takumar lenses, which have a special coupling pin to transmit aperture data to the body (give it a googling). Otherwise, I think you have to settle for stop-down metering.
All the other Spotmatic models are very small, nicely built cameras, with metering, flash synch, shutter delay action (except on the 500 and 1000 models). The best manual spottie is the F model, because you can do open-aperture metering on it with SMC taks.