I'm partial to the picture #3, as that's a pic of the blower in my kegerator
I found the identical blower, and bracket, that MM sells, for much less in the Grainger catalog. It's probably cheaper becauser Grainger is a HUGE industrial supply company.
I took the blower with me to Lowes, and went to the plumbing aisle and looked through fittings until I could find one that would fit the exhaust hole. Notice how one end is barbed, to facilitate pushing the tube over it?
The threaded end fit perfectly in the hole of the blower. In fact, I just hand-tightened, then cinched down with a pair of pliers.
After that, I went to the aisle that sells vinyl tubing, and found one that would fit snugly over the barbed end. The fitting was cheap, (a couple of bucks maybe?), and the tubing was something like $.36 per foot.