as rumble said you are gold with the dual with pushrod oiling- helps not pushing the pushrod through the rocker
better rockers
I hope you are thinking Iron with bushings on chrome shafts- ask rocker arm rebuilders which is the current best setup
HARD triple copper> nickel > grind> chrome od home or chrome moly case hardened
forget roller tips unless you plan on relocating your shafts with a B3 kit or similar
lots of very wrong length roller tip rockers out there
in either case you are better off with cup adjusters and ball and ball (both ends round) pushrods
I've run stock rockers to the .550 area where required by the rules- no problem unless the spring pressure goes high