Hi Egghead,
There are so many variables involved in how each person will interact with a mattress that the most accurate way to know how a mattress may feel or perform for you is through testing a very similar mattress locally in person.
If this is not possible (and I would make this a priority if possible) … then the next best way is with a more detailed conversation with the retailer or manufacturer who can give you good information that will help you understand the pros and cons of the options they provide.
Dunlop has a higher “support factor” and will feel firmer and more supportive than a similar ILD of Talalay. It is also a little less lively. It’s difficult to describe the difference to someone that hasn’t tested both in person but post #7 here may help you “imagine” the difference.
Because there are too many variable involved to make any specific design suggestions for the members here (I leave that to your own local testing, research, and more detailed conversations with each manufacturer) … the “Putting the layers together” and the “Sleeping style, preferences, and statistics” sections of the site and the 'tips and tricks" page may give you some helpful insights. Bear in mind that heavier or larger people may need thicker/firmer comfort layers (as well as firmer support layers) than average depending on their sleeping style and positions and side sleepers will usually do better with thicker comfort layers as well. Because of your weight … a firm Dunlop core sounds like a reasonable choice to me. For the comfort layer which provides much of the “feel” of a mattress … I would rely on any local testing you have done along with the insights provided by APM and your research on this site to make the choice that has the best odds of providing you with the PPP (Pressure relief, Posture and alignment, and Personal preferences) that is best for you.
Phoenix