Hi izzy,
The choice between Talalay and Dunlop is a personal preference and not a matter of “better or worse”. You can read a little more about the differences between them in this article and in post #2 here. Because of the higher compression modulus of Dunlop (it gets firmer faster as you sink into it) I would probably lean towards Dunlop because of your greater weight (you won’t sink in quite as far as you would with the same softness level of Talalay) but your own experience would be a better guideline because both would be suitable for your weight in the right design and firmness level.
I can only speak to the quality or value of a mattress not to individual comfort choices but mattress firmness/comfort levels in post #2 here which I linked earlier includes links to some generic guidelines which may be helpful. Your own testing and experience is the best way to choose both the type of latex, the firmness level, and the design of the mattress and will be more accurate than any “theory at a distance” I could provide.
I also place a high value on the knowledge and experience of the retailer or manufacturer you are dealing with and there may be some better options in your area that you don’t know about (unless you’ve found the closest list to your area on the forum already). If you let me know your city or zip I’d be happy to let you know of any I’m aware of.
Phoenix