Hi Hornickel,
Your mattress wouldn’t be all memory foam (memory foam isn’t firm enough to be used as a support material so it’s only used in the upper layers of a mattress) but if you know the manufacturer and model of your mattress and it was a good “match” for you then it could be a good starting point for your research.
Outside of the “regular” information in the tutorial that would apply to everyone … there is some information in post #3 here and the posts it links to that will be helpful for those that are in higher weight ranges where firmer materials and more durable materials will generally be more important.
There is a big difference between the feel and performance of latex and memory foam so it may be worth testing a range of both of them to help you decide between them and eliminate one or the other. There is more about how they compare in post #2 here.
While preferences play a big role in the “other activities” that can happen on a mattress besides sleeping … more people tend to prefer more resilient materials that are less “motion restricting” than memory foam than the other way around (see post #2 here).
There is more about the different ways to choose a mattress (either locally or online) that is the most suitable “match” for your specific needs and preferences and how to identify and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them in post #2 here. I would always keep in mind that the only way to know whether any mattress is suitable for you with any certainty will be based on your own careful testing (hopefully using the testing guidelines in the tutorial) or your actual sleeping experience.
The better options or possibilities I’m aware of in the Chicago region (subject to the quality/value guidelines here) are listed in posts #2 and #4 here. If I was in the area I would make sure to include Quality Sleep Shop/My Green Mattress in your research. They are one of the members of the site which means that I think very highly of them and I believe they compete well with the best in the industry in terms of their quality, value, service, and transparency.
Phoenix