I bought all three of my PST's (two 600r's and one 1300r) from Dean at http://www.helijet.ca/ who imports them from Thailand.
I have had Carlos at RTI service my 600's and had the factory upgrade my first 600 to the 600r.

Frank Tiano at http://www.franktiano.com/ also sells them also.
I have had good support over the last three years so that is why I have stayed with PST.

Roy