Hi lebaryo,
The choice between Dunlop and Talalay in either a support layer or a comfort layer is only a matter of preference. They are both great quality and durable materials but they are different from each other (see post #7 here). Ideal is what works better for each person in a specific mattress based on their own criteria and PPP (Posture and alignment, Pressure relief, and personal preferences). Once certainly isn’t “better” than another or “more ideal”.
If you go to a place that offers both (such as Foam Sweet foam or any others that have both options available) then you would have a more accurate sense of which one you tend to prefer in either comfort layers or support layers or both.
Yes … Pure Latex Bliss is owned by one of the two producers of Talalay latex in the western world so it would make sense that they would use Talalay in all their layers. I would also keep in mind that PLB has MAP pricing which means that their minimum advertised price or the price they can give you over the phone may be different from what is actually available at the store … especially if you can show them a similar mattress design that uses the same materials at a lower cost (which is the most effective method of “negotiation” for mattresses or retailers where the selling price can vary and isn’t necessarily the best value they can offer.
Phoenix