You might try the annual issue of Multihulls magazine, where publisher lists all known mfrs, clubs, associations, etc for multihulls.

A quick google for pcat, p-cat or pacific cat was not very fruitful. Found at least one race result where someone raced a PCat in last 2 years.

http://old.cruisingworld.com/anothero.htm

http://www.dcss.org/ayrs/12C.html

http://www.mobileyachtclub.com/resod.htm

http://www.duckworksmagazine.com/reports/2002/02/reports.htm