I don't know that 308s are the best iron head out there but they are a pretty significant improvement over the early heads and are the most widely available at a reasonable price. IMO, I'd say W2s are the best iron head with some of the Mopar Performance hybrid LA/Magnum heads offered through the 90s coming in second.
Yes, AMC lifters were the hot ticket for this conversion, back in the 90s. Since then, I believe a couple of lifter companies have closed and/or been bought out and I believe now all Mopar/AMC lifters are considered interchangeable and oil through the body. Use hollow pushrods for rocker oiling or solid pushrods to plug em off. I'd verify it with your favorite cam company before installing though.
Yes, this conversion requires the heads, lifters, pushrods and a modified intake. If you already have the dual pattern intake and the magnum engine, most the parts are there for you already.