Im not totally against the idea of a shirt for each region, but if someone at the club thinks that they can produce a few hundred of these and expect to sell them all, theyre dreaming.
A better idea would be to create an Auckland kit, Canterbury kit... etc, have something unique printed on the front like 'Wellington Phoenix vs *whoever*, Eden park, Auckland, <insert date here>" , and then sell those 15 or so shirts on Trade Me as theyve always done with these one off kits.