Juicer is probably the most specialized - many of the ones I've seen are likely to not work as well anally as vaginally.
For the other two I have and routinely enjoy both plugs and dildos. If you play around with fingers or other items ask yourself what stimulation you like best - if it's a thrusting stimulation then you'll want a dildo. If it's a toys that you can insert and will stay in place than you'll probably want a plug.
In the end you'll probably wind up with both if you like anal play. Do make sure to get easy-to-care-for and bodysafe toys (silicone, glass, stainless, and the like).