FlyerTalk Evangelist, Ambassador: World of Hyatt
Join Date: Jul 2001
Location: NJ
Programs: Hyatt Globalist, Fairmont Lifetime Plat, UA Silver, dirt elsewhere
Posts: 46,919
Costco is probably your best bet. Other than that, there's a Food Lion (I think that's the name) in Koloa across from the post office.
Others may be more familiar than I with the area, but I've hit both those stores.