I am using a Jobo CPP-2 with slides and it works very well. I bought it already with the "lift" accessory. The lift is not strictly necessary, but makes life easier. With a Jobo CPP-2 and a lift, even slide developing becomes foolproof.
You can use both the 1500 series of tanks, and the 2500 series. The former is narrower and allows for a minimal use of chemistry. Two 135 rolls with 240 ml. The 2500 series is larger, you need more chemistry, but somebody says it favours uniformity of treatment better. If you buy a "lift" you need, as already said, the "cog". You can either find some tanks with the cog already fitted, or you can find cogs separately, that you can fit yourself on a Jobo tank.
If your Jobo machine does not have a lift, you need to have tanks with a magnet on the bottom.
As far as other accessories are concerned, I bought an aquarium thermometer which I use to keep some bottles of water warm. This water is the one used for washing during processing, and after processing. I also bought a film dryer which I find very convenient, but again it is not necessary. I bought a Paterson triple stopwatch but I found it is redundant, the only bath for which time is critical is the first bath so any stopwatch with 1 second accuracy would be fine, it should beep though to awake your attention when it is needed.
I bought a large UPS (uninterruptible power supply) so that if I have an electricity interruption I can go on finishing the first developing and the washing with water, after which I can wait for electricity to be resumed, bring everything back in temperature, and go on with subsequent treatment baths. My UPS is pretty big. You would need a "pure sine wave" UPS for the motor but, considering this is going to be used very occasionally, and only for a few minutes, I suspect a normal "square wave" UPS would go. If the load of the Jobo is too much for your UPS, you just turn off the heater and the pump, the important is that the motor can go on until end of developing (& end of washing).
The same paranoid mentality has me have a pocket lamp at hand, in case the electricity goes away and I remain in the dark.
You might need some graduated cylinders to mix the chemistry. If you are not a glass wearer, you should use some protection for your eyes anyway while working with chemistry.
A drying cabinet is especially nice with slides, as high-temperature drying helps long-term conservation of slides.
Fabrizio