I can't add much but I can tell you what has been working for my W2 motor. My cam is a solid roller around 270@.050 and lift at the valve is around .610 IIRC. I run an old Mopar Performance lifter made by crane. Originally I ran Erson W2 rocker arms but I had one of them lose the need bearings so I moved to harland sharp rockers. I have a few thousand miles and a hundred or so passes on the HS rocker arms and they are working good. They have held up well, I recently freshened up the valve job and took the rockers off the shafts and it all looked brand new still. They did need a fair amount of shimming to get them moved on the valve tips properly. They had a decent sweep pattern but weren't centered on the valve well, but I was able to shim them around and line it up better.

I don't see how an offset lifter could hurt anything, it can't make the pushrod angle worse and it will probably lessen the lift loss to the 59" and offset rocker. I don't recall my exact number but mine loses a lot of lift on the intake.