Here is the bench that I'm working on. Basically as simple as it gets. 2" pipe to keep velocities high and 10 times diameter rule after bends/restrictions/before and after pitots. The only bend is a 90 degree to go up to the top of the bench. Unfortunately I don't really have any more room in my garage to go side-ways, besides cutting through existing benches which may have worked... but either way, I still decided to have longer section of pipe go up. If I hadn't already drilled holes in the side of the vac box, I would have put a couple of 90s on the bottom of the box after the casters were on instead of the straight pipes to lower the working side of the bench down where I was originally thinking it would be... as it is now, I have to build a small working step. The last pictures makes it look like less room then there is for a guys head. With the casters on the vac box it's easily moveable to reverse direction of flow.
I had originally planned for 4 or so vacuum motors and I kept having shop vacs donated so I kept adding them. Most of the motors are different, so it will take a little longer setting up the bench in that respect, but I should have various ranges to choose from. I read about someones bench built with MDF 'blowing' up when accidentally sealed it one day, so I added enough bracing to prevent it from happening even if I left my hand over the pipe all day (or so I figure).
Still working on manometers and adapter plates and such, but I'll post a few more of those come time.
I should actually take a few minutes one day and put this on a web page and link to it, instead of having it all in one post.