Hi alohabob,
*EDIT: Just talked with Greg…the core is similar in firmness to the Eco model.
He also said shipping it to Hawaii is very expensive…Doh!
The 7 zone Dunlop was the one I meant to link (I linked the page that had both the eco models and their dunlop/poly hybrid). Even with expensive shipping it would still probably be good value compared to what is there (although the Ironman for king also sounds good to me). It has a 3" Dunlop comfort layer (which gets firmer faster than talalay) and uses a 3" comfort layer so it may be OK with your weight. Did you talk with Greg about whether it may work for you?
As a side note … Brooklyn Bedding (who makes the Dreamfoam Ultimate Dreams) and Arizona Premium Mattress are two different companies.
Geoff at http://www.sleepys.ca/ carries the Ironman and is very knowledgeable about them (and likes them a lot) so he may be able to help give you some guidance on how suitable they may be or some of the layering even though they are in Canada and wouldn’t be selling it to you. He is a good guy. There are some comments about them on their facebook page as well. Latex is a very durable material and there’s no doubt that if the model you get has latex on top that it will last. The only question mark would be the ones with memory foam because I don’t know the density but Geoff may help here.
Another option would be to talk with a local polyfoam supplier and order some known polyfoam (to make sure it was suitable and good quality) and then order a latex topper and a cover. There are some DIY sources here (for ordering separate layers rather than all from a single manufacturer) but the more you can order locally the better for shipping.
Phoenix