You should check out:
www.konaweb.com where there is a very active visiting Forum also pick up a copy of Big Island Revealed. Across the street from the King Kam is Quinn's a local bar. The Kona Brewing Company is also within walking distance. Going South on Alii Drive There are: Fish Hopper, Tante's, Kona Inn, Bubba Gumps, Outback Steak House, Humpy's. Ocean's, Lulu's, Bongo Ben's and Huggo's. The question will be how many will be open that late. Kona is not known for its night life. Enjoy your stay.