Hi tdvent,
Post #2 here includes the better options or possibilities in the Kansas City area that I’m aware of including two factory direct manufacturers that are within reasonable driving distance and may be worth a phone call and/or a visit.
An innerspring is generally a support component (although there are also what are called microcoils which are like mini innersprings that are used in the comfort layers) and can use any type of comfort layers or foam on top of the springs. Memory foam on the other hand is a comfort layer material (all memory foam is too soft to be used as a support layer) so a mattress could use both materials in the same mattress (memory foam over an innerspring for example). Most memory foam mattresses though use polyurethane support layers rather than an innerspring and this would be a “typical” memory foam mattress construction.
Hope this helps
Phoenix