Don't know specific models, particularly if you include used options (+1). I would make sure that
1) you can set different resistance values for your MC cart, as it affects sound profoundly;
2) the settings are available from the front. Dip switches on the back or underneath the unit (or even inside: yikes) are pain to work with, IMHO. Even is you only play around in the beginning, dials/switches not in front are impeding you to adjust the unit to its fullest potential.
my 2c.