In theory, those products are not supposed to be sold on-line except by Crutchfield, and maybe Circuit City.
But if you go to http://www.google.com, and put in the model number you want, you may find it. If you get junk results, add "Alpine" and maybe "buy" in the search box.
or you could try sounddomain, mmxpress, ikesounds, thezeb, any of those will work fine for you. many different companies are allowed to deal with alpine online why do you say that they aren't??