when you say better than store bought that will be very difficult at this point. in lets say 1990 when there was only coke pepsi 7 up etc, id say thats easy. they taste mostly artificial. with a lot of hfcs. mexican glass coca cola with cane sugar is a lttle better but not much.
now there are so many craft sodas in the store its hard to choose. most are sickeningly sweet but some are very good.
i just had a toscani diet cola that was actually worth the 3 dollar 9 ounce bottle.
so i thinkn you just want quality craft soda on the menu not better than store bought.
homebrewed sodas are good i have done them i think i like the fact that you can control the sweetness more than anything.
quality extracts , flavorings, fresh ingredients are key.
i think the problem would be the market. its still soda and will mostly appeal to kids. if you want to go that way as a gimmick / kids attraction (sounds like you dont) that might have a market.
its not like beer you cant down a few pints. i read on one of these threads someone said whats the point of all the calories if you arent going to get drunk / feel good . crude i know but a little true. especially in todays calorie conscious market.
i dont mean to be negative but i dont see it as profitable. the craft soda market is like a seventy qutratrajillion dollar market (dont quote me) at this point but i think thats prolly on the shelf not on tap .
i had pirate petes once on tap at the NJ pet expo. its very good craft soda. especially the flavor selection. cream birch root beer sasparilla ginger ale. all the real sodas. real good but still almost all the flavors are too sweet for me. but hes got a great gimmick. i think to sell at a brick and mortar restaurant it would have to be attached to a gimmick. i think as menu items it would be passed over.
there are prolly a lot of non alcoholic bars with craft "drinks" / virgin cocktails at this point. that may be another marketing point. those stupid bubble tea drink places are getting to me.
all my two cents
in any case good luck with your endeavour