Recently picked up a Crest CA9 amp... it's a whopping 18 inches deep. Guy at the music store sent me home with a rack case that he was *sure* would be deep enough, but no go. I'm not really seeing depth listed in the specs of cases (SKB, etc.) shown on musiciansfriend.com and the like. I want a medium-duty, 4-6 space rack case that'll be deep enough, and will hopefully be an "off-the-shelf" item rather than a "oh, you'll have to get one that deep custom built" kinda thing. Any suggestions for an online source for such cases? Thanks.