I'm threaded for 3/4x28 tpi on my .338 Lapua. Like you said, my decision was dictated by the muzzle device, as I had an Allen Precision 5-port (large) PainKiller that I wanted to use. When you start getting into the thicker threads, keep in mind whoever is threading the barrel will probably want a specific thread length as well. Mine is .850" but I had to find that out from the brake manufacturer.

I think the 5/8x24 thread pitch would suffice, but I always prefer to overdo something rather than be sorry that I didn't. Ymmv.