Hi 64diver,
Welcome to the Mattress Forum! 
Subject to first confirming that any retailer or manufacturer on the list that you wish to visit is completely transparent (see this article ) and to making sure that any mattress you are considering meets the quality/value guidelines here … the better options or possibilities I’m aware of in and around Myrtle Beach is in post #4 here .
There are many mattresses that are appropriate for power foundations, with all-latex mattresses (or ones with a pocketed spring core) usually being best able to put up with the specific demands and weight concentrations placed upon a mattress by an adjustable bed base. Memory foam mattresses (foam core or pocketed spring core) also tend to work well with adjustable beds. There are also many innerspring mattresses that are now made to be “adjustable bed friendly”, but I would be especially careful of some of these as the componentry within many of these “mainstream mattresses” are below the durability guidelines here.
Let me know if you have any questions on things that you find in your visits to local stores.
Phoenix