My bet is that you hit the Bump Stop.
The KYB GR2 and AGX are the same height as the Stockers.
Try a shorter Damper. The Tokiko Ilumina is supposed to be shorter. Should work fine with your intrax.
As for the Shop; You can buy pretty much anything at Crappy, including the super duper Tokiko. Look in the yellow page, Ottawa has a few Speed Shop. Other possibility would be to phone L&R Racing or Kynetic.
Hope this helps.
Ghislain.