First there were the early mechanical models without a meter and without a battery (AP, S-types and K), then after 1964 the Manual Spotmatics mostly with lightmeter (Spotmatic, SL, Spotmatic II and IIa, SP500, SP1000), and from 1973 the Spotmatic F, Electro Spotmatic, ES, ES II, ES II Motor Drive (last model).
All of them M42 mount and cloth shutter.
The SL (1968-1971?) is the last mechanical model without lightmeter.
The ES and ESII are the only models with a possibility for fully automatic exposure (with S-M-C lenses), I don't know about the Electro Spotmatic but this model was only sold in Japan.
The K-mount camera's appeared in 1975 with KM, KX and K2 as first models.