I feel sorry for my american and canadian friends that this drug is not avialabe for you. Its so damn good.
I just googled why it wont be available, it says
According to William, amisulpride is unlikely ever to be approved by the FDA because the manufacturer must bear the substantial costs of such an approval and the limited market for amisulpride would not justify the expenditure 
It is not at all as sedating as clozapine.  And there is no major weight gain like clozapine. EPS side effects are low with doses of 50mg - 300mg.  There is no drug interactions  Its as good as clozapine for positive symptoms.  The only problem is high prolactin, well you have to accept it as a cost as overall benefit outweighs the cost. 
If you want to compare amisulpride with other antipsychotics, check these 2 studies 
 IN THE MATTER OF MICHAEL J. FALLON :: 2009 :: New Jersey Superior Court, Appellate Division - Unpublished Opinions Decisions :: New Jersey Case Law :: New Jersey Law :: US Law :: Justia.