No matter what you buy, do the geometry yourself. No, "use lash caps" is not technical advice, it's just what people say.
Get the pushrods afterward.
In terms of improved breathing: if you cam is too small (and it looks mild to me) 1.6 intake rockers will help, but 1.6 exhausts will do less.
If the cam is too big (certainly not yours) increased rocker ratio won't help you.
Needle rocker bearings allow you to restrict rocker oil delivery somewhat. If that's not important to you, you don't need them. I prefer bronze bushings.
1.6 rockers (vs. 1.5) also increase the spring load on the pushrod, adjuster, and tappet by 6.7%: with 500 lb. rated springs at full lift, the 1.5 rocker is 750 lb. on the tappet, a 1.6 rocker will be 800 lb. This is why rockers with 1:1 ratio were popular before WWII: the cams wouldn't take the pressure, all the lift had to be built into the lobe.

Andy, please correct me if I'm wrong here:
1. Mancini's house-brand rockers are made by Harland Sharp
2. Part of why they are less expensive is because they're bushed, instead of using needle bearings (less small pieces to be worried about getting into the engine)

IMO, a quality manufacturer + simpler design + more affordable price = a viable option.

If I thought they were junk, I wouldn't have agreed with Andy's suggestion.

Nobody but the OP can know what changes he's likely to make beyond what he's described above. Sometimes you have to take people at face value, even if you would take a different approach.

I used the Mancini rocker arms on a 700 hp big block with 0.700 lift. So my testing was with a camshaft that is much more aggressive than what the OP is planning to use. The Mancini rocker arms worked just fine in that application so I'd think they would work fine for the OP.

https://www.hotrod.com/articles/trying-find-extra-power-rocker-arm-testing/

Another choice is Hughes rockers.

Brian

The mancini rocker made by HS is not bushed and is not the same body as the standard HS roller rocker - I bought a set for the street car to replace some 440 source roller rockeres I had - The mancini set is good quality but definaetly not as beefy as the regualr HS rocker and I did have to order new pushrods as mine were just about .040 short going from the source rocker.

One quick comment that someone else may have touched on already... some of the rockers being talked about, e.g., the "original" Harland Sharps, have a very long fulcrum that biases the valve tip sweep pattern noticeably to the exhaust side of the tip. Hughes are on the long side, but not to the extreme as the standard Harland Sharps. For some folks this isn't anything they're concerned about. For others (like myself), I don't like to run things that way.

The rockers that I recall that are better suited (not saying "perfect") to being able to bolt down and not have this tendency are Crane Golds, Harland Sharp's "E" rockers (made shorter for Edelbrocks), and -- I think -- COMP's Pro Magnum steel rockers. Oh, and the old RAS stuff I believe falls into this category.

AndyF has done a lot of rocker / head mock-ups and may be willing to comment on this further. And I'd expect that Mike at B3RE can make a shaft relocation kit to help the worst offenders.

Carry on...

I also wander why if its a mild street/strip eng you are going to the best and highest priced ones ? Not being smart just curious as my self I use these Hughes 1.6 roller tip rockers. Been on my mild 493 since 2011 and never a problem. Mine is a street car that I race once or twice a year. Ron