Hi jschiavitti,
There is more about motion transfer in post #18 here. Memory foam is the best at motion transfer but latex, pocket coils, microcoils, buckling column gel, and even polyfoam are generally good as well but it will depend to some degree on the specific design of the mattress, on your relative weight ranges, and your sleeping style (such as how close you sleep together). Innersprings that are linked with helicals (vs pocket coils) are generally poor to fair depending on the specifics of the innerspring and the foam layers above it. The most reliable way to know whether a mattress is “motion isolating enough” would be based on your own careful testing or your own personal experience with both of you on the mattress.
Subject to first confirming that any retailer or manufacturer on the list you wish to deal with is completely transparent (see this article) and to making sure that any mattress you are considering meets the quality/value guidelines here … the better options or possibilities I’m aware of in and around the Buffalo, NY area are listed in post #29 here.
Phoenix