I spent a morning taking some glider demo flights at honolulu soaring/Mr. Bill's (same place) at Dillingham. It's a reasonable drive from HNL - an hour give or take but a very pleasant one.
They have a variety of gliders available including one setup for acro. Very friendly, approachable staff.
They have a variety of tourist-oriented packages but after I flew one of the instructors told me that they let pilots just rent the plane and instructor for what can amount to a better deal than the packages. (Essentially, if the lift is good you only have to pay for a 1000' tow and can then stay aloft as long as you like)
Feel free to PM me.