Hi Jeff,
Post #4 here includes the better choices in both the Wilmington and Philadelphia area that I’m aware of. There are some good latex and memory foam choices on the list and some calls to the ones that are within reasonable driving distance to let them know what you are looking for and to make sure they have something that you want to test should help you decide which ones to visit.
I think it’s probably a very good idea to be cautious about the iComfort. In case you haven’t seen it … the specs of the iComfort line and some comments are included in post #11 here. They are not great.
Phoenix