The hottest LS swap from what i understand is dropping one of these in a nissan S-15 chassis, better known as a 240 SX or Silvia in Japan. Its RWD and light weight. An all aluninum LS6 with stick shift in a 240 SX is insane.
Might wanna keep your eyes peeled...one of the kids I know on base recently blew up the 3.5L V6 in his 350Z...he's going LS too...not sure when or to what extent.