Your Kansas City seller should really have no problem in shipping that sign to you. As long as cost is not a restrictive concern, seller just needs to take the sign to a UPS or Fed ex store and have them tasked with safely packaging and shipping the sign. Double boxing for something like this on a long journey might be advisable.
I have received a 24” x 24” stained glass art piece safely shipped over 1000 miles with no damage. Most shipping businesses have the necessary experience to safely ship just about anything.
Larry