Since you have an interior shop, do the outside however you want to, just so the interior looks great, since that's your showcase. Though from a buisiness standpoint, if its painted up with no patina, everybody will like it fine, with patina, some may not like it and it could scare off a few people, you never know. It all depends on the customers As long as the interior looks great either way should work fine though. Me personally I don't like patina since I was forced for many years to drive pre-patina'd vehicles.
Some of them look good though, but that's because these trucks just look good.
If paint is available and so is money, I will always go for paint asap.