Good question?
On my Victor MW heads, the short valve spring install height, and weak rocker shaft pedestals cast into the head were problem areas.
I ended up milling off the pedestals and using max wedge type rocker shaft blocks. T&D now offers paired shaft rockers that would be a better solution.
If going to custom rocker system, I would use valves with longer stems to make it easier to get more spring install height, then relocate the rockers for best geometry.
If looking for 0.800"+ lift I would use a 1.7:1 intake rocker arm, and for long life, a more gentle cam lobe profile that can be controlled with a lower rate valve spring.
An aggressive cam profile is going to want a high spring rate, which makes things harder on the valve train.
On my current setup, I believe my exhaust profile (Comp HXL) with 1.6:1 rockers is too aggressive. I have though of using a 1.5:1 ratio rocker arm, and a slower opening exhaust lobe profile to take strain off the valve train.
I like the idea of the bushed lifter bores with keyway roller lifters, but have no idea on how they would do with many miles on them? The keyed lifters should be lighter in weight (than the taller roller lifters with the cross bar) making the valve train more stable.
I'm running the PAC 1326 valve springs, but only 0.726" lift. It is 275 seat pressure and 663 spring rate. They list as 805 open pressure @ 0.800"

If you have room for a 1.625" diameter spring, something like the PAC-1328 installs at 2.100" with 280 pounds, and has a spring rate of 629, and at 0.900" lift the pressure is 847 pounds, if that will work with your cam selection?

You would want good oil cooling of the springs too.