From what I have read on here the retail stores do not make on line sales. You could call the store and ask if there is a way for you to purchase the shotgun.

Also found a mossberg 600 in Hawaii on Armslist.com
armslist.com/classifieds/search?search=Mossberg&location=hawaii&category=all&posttype=7&ships=

One available here
https://gunprime.com/products/maverick-88-12-18-5-cyl-bead-sight

If your near that location then you can call them on the phone at 9am when they open and see if you can buy it over the phone that way it doesn't sell out while you're on your way over.
If your not near that location, items in the retail stores are not available to be shipped for online purchases, they must be picked up at the retail location.
Buds Gun Shop & Range
2270 Two Rivers Blvd
Sevierville, TN 37876
865-774-2007
Just noticed the "in Hawaii" part, you won't be able to purchase this, ill look around and see if I can find a site selling one that'll ship to Hawaii