I want to buy an Aneros toy to my bf for his bday

Hi, my boyfriends bday is approaching and I would like to buy him an aneros toy.
I have to say that he is new to this and has never tried anything anal. My ex in comparison really enjoyed it, but he knew himself so well, that I didn’t have to take care of anything (he knew how to ease himself into being able to take up big sizes too, he did the cleansing himself etc. …).
I don’t do anal toys at all on myself so I am not really experienced – thus, I would like to ask:
– should I get him the Helix trident? What is suitable for a beginner?
– I guess he will need an anal doushe too? Can I get any recommendations for that?
– should I get him poppers?? Are there other alternatives to them? (Never used them. Im scared they work similar to drugs)
– I would also like us to use it together on him – meaning maybe having some kind of mutual sexual experience while him using it (I am a woman), do you think this is possible? I don’t know if him having it inside and me stimulating his penis would be the same as me as a woman having a vaginally inserted dildo while the man pleasuring her orally on the clitoris … I assume that he needs to be relaxed w the aneros inside to have some pleasure, no? How should we approach this so it would be a mutually pleasurable experience and that he would be as relaxed as possible anally?
– my idea was to introduce him to this since he enjoys outward prostate stimulation so much. My and ex and me did pegging but I think we can’t start with that and he is open for internal prostate play for starters…