Hello Yeknom02,
CPE 2 and CPA2 are the same, but the CPA has eaten EPO and got bigger...
The CPE2 can't handle 3000 series tanks (too big and too heavy for the motor). CPA/CPP can use every tank the CPE2 use and also the 3000 expert drums.
The CPE2 is limited to 600 CC chemistry (by the torque of the motor) and the CPA/CPP can handle one liter (1000 CC).
This is important to calculate the number of films you can process in one run. (if you plan to process only 35 and 120 mm film only I suggest you get the 1500 series tanks which, as they are smaller in diameter, use less chemistry to wet all the film. )
This said, you can calculate the maximum number of film per run by looking in the chemistry instructions how many CC you need per 135 or 120 film, then dividing 600 for CPE2 or 1000 for CPA2/CPP2 by this amount. (check that the minimum chemistry per film is above the minimum required for your tank to wet all the film, if not use this volume instead)
This may be a better way to choose between the two kind of processors.
As for the temperature control, the CPE/CPA have a knob which must be set for the process temperature. The marking could be wrong, but once you've calibrated which marking is the actual 38.3 ° C it will stick to it at around 0.2°C (this is precise enough for E6 processing).
I'm not a very big fan of the lift. I owned a CPE2 with it and one without it. I kept the one without it.... But your mileage may vary.
Last but not least, either the CPE or CPA are simple mechanical devices with very little electronic inside. You may find people to repair them in the future. The situation is a little bit different for the CPP2 which has more electronic inside. But is is not a device from NASA, so should be able to be repaired for a very long time.