Hi ron bruce,
It sounds like the toppers you’ve tried are too firm and that you need something softer … regardless of the type of material that you prefer.
Latex and memory foam are very different materials with very different properties but the choice between them is more of a preference and budget choice than a “better/worse” choice. There is more about some of the differences between memory foam and latex in post #2 here. Some people tend to prefer the faster response and more resilient and “on the mattress” feel of latex and some prefer the slower response and more “in the mattress” feel of memory foam but the best way to know which type of materials or mattresses you tend to prefer in general terms would be based on your own careful testing and/or your own personal experience with each material in a range of different firmness levels.
I’m guessing that the “cool type” memory foam you are referring to are the many different gel memory foam materials that are available on the market. If that’s the case … the “hand feel” of most gel memory foams will be noticeably cooler than regular memory foam and they can provide some cooling benefits when you first go to sleep at night but temperatures will tend to equalize over time at which point the insulating properties of the memory foam will become dominant. The amount and type of gel in the foam can affect whether the temperature benefits will last longer or shorter and the cell structure and amount of airflow through foam will also play a very significant role in reducing heat buildup in the material but in general terms … gel memory foam can sleep a little cooler when you are first going to sleep at night but in most cases the benefits of the gel tend to be temporary and don’t normally last over the course of the night.
If the only issue with a mattress is that it is too firm and there are no soft spots or sagging in the mattress then a good quality topper can certainly be an effective way to add some additional softness, “comfort” and pressure relief to your sleeping system but the only way to know for certain whether a specific mattress/topper combination is a good “match” for you in terms of comfort, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) is based on your own careful testing or personal experience on the mattress/topper combination. If you can’t test the combination in person then there will always be always some risk and uncertainty involved in adding a topper because the specifics of the mattress itself along with your own body type, sleeping position, and preferences can affect which specific topper would be a suitable choice on any specific mattress.
There is more information about choosing an online topper in post #2 here and the topper guidelines it links to which along with a conversation with a reliable and knowledgeable supplier (that can provide you with good information about how their toppers compare to each other or to other toppers they are familiar with that are available on the market) can help you use your sleeping experience as a reference point and guideline to help you choose the type, thickness, and firmness for a topper that has the least possible risk and the best chance for success.
Outside of any local options that may be available to you … some of the better online options I’m aware of that ship mattresses and/or toppers across Canada are also listed in post #21 here.
A good exchange/return policy can reduce the risk of an online topper purchase so if you aren’t certain whether a topper will work well for you I would always make sure you are comfortable with the options you have available after a purchase just in case the topper you choose doesn’t turn out as well as you hoped for because again … the the only way to know for certain whether a mattress/topper combination will be a good “match” for you will be based on your own careful testing on the combination or your own personal experience when you sleep on it.
Phoenix