Guerlain Homme L'Eau Boisee
Vetiver Frozen (also by Guerlain)
These are two that I think would work really well in the hot weather, as far as vetivers go.
For vetivers that are not specifically geared toward hot weather, consider:
Guerlain Vetiver (though I don't like this one...it's a classic)
Sycomore by Chanel (definitely not for hot weather, but a great vetiver scent).