This post is certainly obsolete...
To select one of the different sleep modes of the Mac use the command-line tool pmset:
To show the current settings:
The hibernatemode can be 3 (default: safeSleep, i.e. the RAM content is also written to disk when the lid is closed), 0 (pure RAM sleep), 1 (pure deep-sleep). Turn the safeSleep off:
sudo pmset -a hibernatemode 0