I used to have some figures for Royal Purple. They do disclose more than what actually appears on their website. Product data sheets, oddly enough, don't appear on their website, at least not easily, and you can find them by Google. XPR is their racing oil, and HPS is their street/sport oil. They also have SN/GF-5 rated oil.
2200 ppm of ZDDP is a little high in my view, to the point of being corrosive. I would assume that the "normal" RedLine stuff would have an elevated level of ZDDP in the ranges you're looking for.
Royal Purple (HPS or the older stock SL versions) would also do the trick. They won't have corrosive amounts of ZDDP. Both regular RedLine and Royal Purple HPS or SL rated oils should have ZDDP levels that were considered acceptable in the API SL days.
M1's racing oil is also rather high in ZDDP, a little higher than I prefer, but within the ranges you've specified. 1100 or 1200 to 1500 is my preferred range for such motors. You can also get that out of most dual rated HDEOs. I don't know exactly what's available in Australia, but you should be able to find a suitable HDEO conventional in 10w-30 or 15w-40 or synthetic in 0w-40 or 5w-40. I believe Doug Hillary, in Australia, uses Mobil Delvac 1 5w-40 in CI-4+ API rating, probably with SL as the gasoline rating.
Up here, a lot of classic performance car enthusiasts have used API SL Royal Purple for the ZDDP levels. My view, though, is that synthetic oil in general is a very expensive option for a carbureted engine.
There's another issue to consider. Are you going to only be racing or is it something you're going to drive around? Most racing oils do not have much in the way of detergents, so they have to be changed more often. If they're expensive, racing synthetics, that merely compounds the problem. The street lines of Royal Purple (which really includes HPS and the old stock SL if still available) will have plenty of detergent, whereas XPR and other dedicated racing oils may have much less. They're all great oils, but costly and less durable from a carbureted daily driver standpoint.
That's why I like the conventional HDEOs. There's enough ZDDP and detergent, and if you're changing the oil regularly because of fuel dilution, at least you're not spending huge dollars on the oil in the first place.