I would first try MGM as he has the better prices, but here is a list of stores where you can try out different ukes. Beware, the Waikiki ones will have higher prices.
Aloha Ukulele
2005 Kalia Tower
Hilton Hawaiian Village Resort
Waikiki, Honolulu, Hawaii 96815
Phone: 808-955-5295
Bob's Ukulele
Waikiki Beach Marriott Hotel
2552 Kalakaua Avenue
Waikiki, Honolulu, Oahu, Hawaii 96815
Phone: 808-372-9623
Ukulele House - Waikiki
Waikiki Shopping Plaza
2250 Kalakaua Avenue
Waikiki, Honolulu, Oahu, Hawaii
Ukulele PuaPua
Sheraton Waikiki 2255 Kalakaua Ave. #18 Honolulu, Hawaii 96815 U.S.A. (808)923-9977
-Moana Surfrider 2365 Kalakaua Ave. DHW #5, Honolulu HI. 96815 U.S.A. (808)923-9977
Hawaiian Ukulele Company - Aloha Tower
Aloha Tower Marketplace
1 Aloha Tower Drive
Honolulu, Hawaii 96813
Phone: 808-536-3228
Island Guitars - Ward Wareouse
Ward Warehouse Shopping Center
1050 Ala Moana Boulevard
Honolulu, Oahu, Hawaii 96814
Phone: 808-591-2910
Dan's Guitars
2000 South Beritania Street
Honolulu, Oahu Hawaii 96826
Phone 808-942-2900
Easy Music Center
1314 South King Street
Honolulu, Oahu, Hawwaii
Phone: 808-591-0999
Goodguys Music and Sound
619 Kapahulu Avenue
Honolulu, Oahu, Hawaii 96816
Phone: 808-732-4663
Hawaii Music Supply - Wahiawa
Kamehameha Highway
Wahiawa, Central Oahu, Hawaii 96786
Phone: 808-622-8000
Easy Music Center - Pearl City
98-425 Kamehameha Highway
Pearl City, Oahu, Hawaii 96782
Phone: 808-484-1360