AutoArt is good and probably has the SLS... there's a lot of other highend ones like BBR and LooksSmart and Peako, etc... but they focus on Italian cars mostly. Peako makes some pretty crazy Lexus LF-A models though, but they just started so I've heard of some quality issues on their Pagani line... look beautiful from the pictures I've seen though, real carbon fibre weave and everything.
I've posted a bunch more models for sale too... all NIP:
http://www.revscene.net/forums/67621...st-models.html