All GM valve rockers (gas or diesel) that I'm aware of (OE or aftermarket) are pressure fed with oil from the tips of the pushrods.
The very first 6.2L diesel valve rockers were made from cast-iron, they were heavy and their bronze bushings wore out sooner than the later stamped-steel versions. There was a definite need for an upgrade in the early 1980s.
The factory stamped-steel rockers that replaced the earlier versions work so well that I can't see a reason or need for an upgrade. The roller tips sound like a great idea, but I'm not aware of a problem with tip or valve stem wear.
The OE rockers are held centered over each valve using a plastic button. This button has been a problem for a few folks. Inventive owners have devised a couple of workable solutions for this rare problem, and I think it wouldn't be time wasted doing something that eliminated the plastic button.
While I encourage and applaud experimentation, I don't think roller rockers are enough of an improvement to warrant much expense or effort over that required when using the OE versions.
Through the years, there have been a number of vendors who tried to develop a unique product for the 6.5 that set them apart from the crowd. They tended to focus on products that were originally essential for the performance gas engine market, but adapted for the 6.2/6.5. What they don't consider (or maybe they do) is that these diesel engines turn at half or less the RPM of a performance gas engine. The flow dynamics are way different, and the requirements for efficiently moving air/exhaust through the engine are way different.
For example, ported and polished heads produce a worthwhile advantage on a performance gas engine, but it's mostly wasted effort on a diesel. Lightweight or space-age valve train components produce a significant return on a high-revving gas engine, but again, this is mostly wasted on a low RPM diesel.
When a stock OE valve train part can function as intended for hundreds of thousands of miles without a downside, I don't see a need for an "upgrade".
Jeep, experimentation is what has produced all the proven useful upgrades we're seen through the years. However, there is a small number of products out there that can't be proven to provide a benefit or may actually cause a problem. Look for genuine value. Look for verifiable proof. Jim