That will be a wonderful shop with plenty of space.  +1 on Pottz comment.  Take some time to watch some of the Oneida DC videos even if you don't buy their product.  They talk about proper DC piping design.  There are also a lot o good Youtube videos out there.  Do it right the first time.  I tried just about every type of DC and messed around with various piping designs, partly because I'm an engineer, and realized that a lot of the hype around the various DC is just that.  There is a reason commercial DC is run overhead.