In Wailea, Mulligans can have a good crowd, esp. on weekends. In south Kihei behind the open air market with the roof is "barmuda triangle", not sure what 3 bars are there right now but there is usually a good crowd in those places also.
I've always gone with girlfriends and never end up getting to golf very much, end up sitting by the pool, shopping, blah, blah, blah... I think it would be blast to go with a buddy or two and surf, scuba, golf, and drink lots of primos. There are single girls in Kihei, you just have find them.