PCV part number is 12204-88570, it is specific to the Altezza's 3SGE unfortunatly. I work at a Toyota dealer here in NZ. We have thousands of Altezza on the roads here. At their peak it was well over 10,000.
I've never heard of a "J" Edition, there's Z & L Editions though. You'll find the letter at the end of your model number if it is one. This site will help you identify what model you have http://www.japanvehicles.com/newcars/toyota/Altezza/equipRS200.htm & http://www.japanvehicles.com/newcars/toyota/Altezza/main.htm
Do yourself a favour when it comes to servicing, get your hands on a quality 10W30 like Royal Purple HPS or Redline. Don't waste your time with cheap semi synthetic especially 10W40, if you must run a 40 weight then a thin full synthetic like 0W40 Mobil1 or 5W40 Shell Helix is next best the way to go. Another very good option is Motul 300V 5W30 if your budget alows it. Thats what I run in mine.
As for performance parts, put a K&N panel filter in & some Iridium spark plugs for a start. Then upgrade the exhaust. Add an LSD if it doesn't have one. There's not much else you can do without spending big money like upgrading the ECU to an Apexi Power FC or Turboing. Most people just make do & upgrade the suspension.