Hi DCGiggles,
It would be hard for me to imagine that 3" of 14 ILD blended Talalay would be too firm for almost anyone but of course each person is unique and there are also many variables that can affect your experience on a mattress/topper combination outside of the topper itself. It may also have to do with the firmness of your mattress underneath it or your body weight and sleeping style as well. It could also be that you just don’t like the “feel” or resilience of latex regardless of its firmness level. In some cases if a topper is too soft and you are in a higher weight range then you may also feel more of the firmness of the layers underneath it and in some cases an ultra soft topper can feel firmer than a topper that is slightly firmer where there isn’t as big a transition between the topper and the firmness of a mattress underneath it.
In any case … other types of materials will have a different “feel” from latex and unfortunately I can’t make any specific suggestions because you are the only one that can feel what you feel on a mattress/topper combination and there are too many unknowns, variables, and personal preferences involved for anyone to be able to predict or make a specific suggestion about which topper would be the best “match” for both you and the mattress you are using it on in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own personal testing or sleeping experience (see mattress firmness/comfort levels in post #2 here). As an example of this I would never have guessed that a 3" 14 ILD talalay latex topper would be too firm for anyone and for most people I would normally suggest something a little bit firmer unless they are in a lower weight range but there are always exceptions to every rule and the averages of other people.
Some types of higher density and more highly resilient polyfoam in lower ILD ranges will probably be the most closely comparable foam material to softer latex
Phoenix