Here is my summary. I have been doing lots of reading and essentially settled on the simplest pressurized storage setup with one minor modification in that I have two different temp areas. My thought was I wanted to keep pumps to a minimum so I have mixing valves for temps and a pump for each temp area, with zone valves in each of these zones. My concern of late is the piping that essentially is between the zones/wood boiler/storage/backup boiler and if I need to follow primary/secondary piping, and if so do I need another pump? Also note that It is a rough drawing and not everything down to the ball valve is represented fully.