Hi Les167,
This is a very broad question and would depend on what you consider to be a suitable alternative. Almost all latex is a high quality material and there are many manufacturers across the country that use it in their mattresses so any alternatives would depend on where you are, what is available to you, and on the specifics of what is important to you in terms of the type of latex in a mattress and based on your personal value equation as well. There is more about the different types of latex in this article and in post #6 here.
Latex also comes in a very wide range of softness levels so other latex mattresses may use the same type or quality of latex but the design may be different which means that it will feel and perform differently for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
There is more about trying to “match” another mattress in post #9 here but the first place to start when you are looking for a new mattress is post #1 here which has all the basic information, steps, and guidelines you will need to make the best possible decision for your own personal criteria.
If you find out the specifics of all the layers of the mattress you are considering at SB mattress (which is an important part of any purchase decision) and post the information here I’d be happy to make some comments about it as well.
Phoenix