Hi kgroth,
I switched your post to a new topic of it’s own so your questions and comments wouldn’t get mixed in with another member’s topic.
The most common allergies are to dust mite particles and other airborne small particles rather than the materials in a mattress. There is more information about dust mites and allergies and methods that can be used to control dust mite populations or other allergens in post #2 here and in post #3 here. There is also more about allergy encasements in post #2 here.
The choice between Dunlop and talalay is a preference choice not a “better/worse” choice. There is more about the differences between them in post #7 here but the best way to know which type of latex you tend to prefer will be based on your own testing and personal experience.
There is also more about the different types and blends of latex in post #6 here but both Talalay and Dunlop come in 100% natural versions (which don’t contain any synthetic rubber in the formulation) and in blended versions (which contain a blend of natural and synthetic rubber in the formulation). All latex formulations including 100% natural latex (Dunlop and Talalay) also contain other substances such as foaming agents, curing agents, antioxidants and others besides just the rubber that is used to make the latex core (see the first part of post #2 here).
You may have seen this already but just in case you haven’t … the better options or possibilities I’m aware of in and around the Seattle area (subject to making sure that any mattress you are considering meets the quality/value guidelines here) are listed in post #2 here.
I’m looking forward to finding out what you end up deciding … and of course any other comments or questions you may have along the way.
Phoenix