No pistol build can have a vertical grip, at all. Otherwise, it's not a "pistol" anymore. That's BATFE, and it doesn't matter what any state says about it. Adding a vertical grip to a pistol build converts it directly into an AOW, and you have to pay for it and wait, through BATFE.
If it's a pistol, and it's over 26" long, it falls into some weirdass category. That's how Franklin Armory got over on the AFT, and made this thing, WITH a vertical grip...
http://www.thetruthaboutguns.com/2011/10/foghorn/franklin-armorys-new-ar-15-is-neither-a-pistol-nor-a-rifle/