Earliest A-Mount Body?
The first A mount camera was the Minolta 7000 and came out circa 1985. It was the first production autofocus 35mm slr. I still hav my fathers 7000 with crossed X's, the camer I learned photography on. You can pickup a workin 7000 for about $20. It was a gret camera.
The Maxxum 7 was the best SLR ever made. That is what I would get for shooting film if I were you.
Your APS A mount lenses will vignette (have dark corners) on full frame 35mm camera like the ones listed above.