There are the three major reamer makers currently in use for cutting chambers. JGS, Manson, P,T& G. All three are perfectly capable of producing reamers from SAAMI spec to full custom dimensions. I have used them all over 30+ years of chambering barrels.
Your question though is kind of like which came first, the chicken or the egg?
Deciding on a bullet first then designing a reamer around your thinking can lead to needing more than one reamer if the first doesn't prove out to be satisfactory. I would call Hammer Bullets to discuss your thinking first and hear what they have to say about your choices before getting in line and waiting several months for a guess and by gosh reamer. You may find that there is already a design which will suit your thinking.
I have a couple of basic .264 Win Mag reamers but I have necking and throating reamers for adjusting the chamber when necessary. You might also want to consult a gunsmith before deciding also. You might be surprised at the information available from an experienced gunsmith.