Not to get sidetracked off of the pourover, but what kind of espresso machine are you going to use in the shop? Have you considered getting a tap installed in the countertop for selter water? That same Intelli location introduced me to seltzer water with, but separate from, your espresso. They give you a demi, plate and spoon for the espresso and a tiny rocks glass full of carbonated water from the tap that might be 3-4oz. I find it to be very nice and refreshing. It works really well as a palate cleanser between shots of different espresso.
As well as it works I think stuff like that is an important part of giving your shop an identity. I have not seen any other shops that do this, although I am sure several do. One thing I can guarantee though is that no generic run of the mill shop would do such a thing.
Oh the other place I saw this was at New Belgium Brewery in Fort Collins, CO. They actually had flavored seltzer to cleanse the palate between beers. The day I stopped in it was cranberry. You could either have plain or flavored. The flavored could get cool, as long as it was subtle, if you play to the noted of your particular espresso, i.e. strawberry, blackberry, meyer lemon, etc.