Hi eafrey,
The choice of material in a topper would be a personal preference more than anything else so I can’t really help with this but post #3 here and the topper guidelines it links to along with your own personal testing on different types of materials to find out which materials you tend to prefer should help you choose a topper that has the best chance of success … or at least the lowest risk. It also includes a link to a list of the better online topper sources I’m aware of.
If each of you have a very different body type and have different needs and preferences in terms of PPP then it may also be worth considering different toppers on each side of your mattress. For those who like how it feels (and not everyone does so I would test some mattresses that use different types and firmness levels of latex in the comfort layers to get a sense of what different types and firmness levels of latex feel like) … latex can make a good choice because it has properties that can be both soft and contouring and more “supportive” than other types of foam at the same time.
Their polyfoam is CertiPur certified but that would also be true for almost all the polyfoam that was manufactured in North America so if you are OK with the polyfoam that they use then you would probably be fine with any other polyfoam topper that was CertiPur certified or made in North America in a suitable firmness level. If you do decide to use polyfoam I would also make sure that it was a good quality and durable material as well which would be in the range of 1.8 lb density or higher (Tuft & Needle uses 1.8 - 2.0 lb polyfoam) depending on your weight.
Phoenix