Hi tcornflake,
I don’t know the specifics of the Amerisleep foundation but they should be able to tell you. Normally the foundation that is sold by the manufacturer would be a suitable choice. With a memory foam mattress that has a polyfoam base the gaps can be wider than a mattress that has a latex base layer although more slats would provide more even support for any mattress and if the value is better then it may make a better choice. Any of the foundations listed in the first post of this thread would also be fine (and may be better quality and value than their own foundation once you find out the specifics) although it’s always a good idea to make sure that a foundation meets the warranty requirements of the manufacturer.
Phoenix