You know, with the introduction of New Haven, I don't see why anyone would even bother with a custom character anymore, except for tamers and bards.
Hiding and Stealth can be bought and/or quick-trained to the "custom" levels in New Haven, and it would be better IMO to pick the standard character type closest to the other skills you'll want on the character, then get the Hiding & Stealth quests at the place where Ninjitsu & Tracking also have quests.