Eh, I don't like shows with lots of yelling (American Choppers and Ax Men come to mind immediately) and I always find it funny when shows start adding in women to get more people to watch it (think Ice Road Truckers).
I think a show about custom tanks (preferably freshwater) would be good just by itself - you can have the customer explaining what they want, the tank build, the installation, the tank set up (lighting, decor, plants, etc), the stocking, etc. Sure, the customer will probably change their minds several times throughout the process so that could be the 'drama'. But I'd watch it even if things went smoothly every time.