The best places are universities like UND or Purdue who have advanced aircraft training programs. I believe ATP and RAA also have CRJ training programs for folks with more money than sense. But rick is 100% right. Save your money. Those programs cost $3000-$5000. You're better of spending that money on an MEI or just tooling around in a twin building some PIC time. That makes you more marketable to anyone, not just places that like to see an "advanced aircraft" course.