Hi yourconfused,
Most of the foam suppliers only ship through UPS because shipping through truck freight is just too expensive. This means that outside of locally or regionally, they can only ship foam of a certain size or thickness for it to be economical. some of them though do have a machine that will compress the foam before shipping and these ones can ship larger sizes through UPS and stay within the size restrictions.
At this point I don’t have a list of which is which because polyfoam is not a commonly ordered material as separate components and in most cases there are local foam shops where this can be purchased but over time as I find them I’ll list the ones that are knowledgeable and sell good quality foam and also have the ability to ship any size across the country for those that want to order foam this way. Some of the ones on the list may be able to do this although as you discovered A-1 isn’t one of them. Latex and memory foam layers are much easier to order in larger sizes.
One way around this as long as the layer isn’t too thick would be to order two twin sizes instead of a King but again if it’s too thick then it may also not fit inside the UPS size restrictions.
There is a list of the better manufacturers and retailers in the Austin area in post #2 here. These are mattress manufacturers and retailers though that have better quality, value, and service but if you are looking specifically for polyfoam layers they may not supply these. I don’t know of any local foam shops in the area but I would imagine there are several that a google search would turn up if you are looking to buy plyfoam instead of a mattress.
Hope this helps
Phoenix