I live in Europe and thus Peri RX is quite impossible for me. I currently supplement with Beta alanine and creatin everyday. Between citrulline malate, beta anhydrous and HMB are done of then “Better” than others. I’m a student, so I’ll need to prioritize. And should all three be taken everyday or only pre and post workout?
Getting your recommended protein intake > protein intake timing > everything else.
That said, the science isn’t there yet, but there is reason to believe that HMB supplementation may be beneficial if you are in a caloric deficit, so I’d recommend it over your other choices for that instance.
Read up here: (You can also use that website to search for info on the other things you are asking about and make your own decisions)