Hmmm...with the exception of trading cards and the action figure, I'm not familiar with any other Dexter items. There is WA-9 (?) the waitress droid and that R4 unit from Dexter's kitchen (availabe in the Entertainment Earth droid pack).
I think there might be a mask.
I guess I'm no help in locating items.
Are there any other items you kow about? I'm curious now.