Hi freitazm.
Congratulations on your weight loss. 
Talalay would have a softer feel and might add just the touch you need for better pressure relief for you. Dunlop and Talalay that are the same thickness and ILD won’t feel the same in terms of their firmness for most people because they have a different response curve and compression modulus (how quickly a material becomes firmer as you sink into it more deeply). Not only that Talalay and Dunlop have a slightly different feel, with Talalay being “springier”, but the biggest difference is that Dunlop “firms up faster” than Talalay, as it is compressed more.
There is also more about the difference between Dunlop and Talalay inpost #7 here.
Good luck with the fine-tuning.
Phoenix