Hi jeremy,
Unfortunately … Dunlop and Talalay firmness ratings don’t compare all that well because of the differences between the two types of latex (see post #7 here) and differences in how ILD is tested (see post #6 here). If you want the “feel” of Talalay then it would need to be Talalay although there are lower cost sources of either 100% natural Talalay or blended Talalay than a PLB topper in the component post I linked earlier (including the two sources mentioned here).
While a Dunlop topper won’t have the “feel” or resilience of a Talalay topper (some people may prefer one over the other because of the differences between them) … 100% natural Dunlop in the 60 kg/m3 or lower would be somewhat “in the range” of the same softness level and some of the continuous pour Dunlop toppers (either synthetic which is less costly or 100% natural) would also be in a somewhat similar softness range. It’s generally much more difficult to find Dunlop that is as soft as the softest Talalay.
I don’t know of any sources for molded Dunlop that is as soft as the Talalay you are looking at but a couple of sources for continuous pour Dunlop toppers that may be “in the range” that would be worth talking to include here (3" toppers in 100% natural continuous pour Dunlop made by Mountaintop foam)
Phoenix