Just as you asked your question I was in the process of acquiring parts for my dust collection system. My shop is my garage and I have several tools I need to hook up. Here's my plan.
I will be getting for free a used furnace fan, the squirrel cage type. I will build a plywood box to house the fan with one side open to provide for exhaust. On one of the plywood sides there will be an opening to hook up a hose probably 3" diameter.
That hose will go to a purchased cyclone probably from Oneida
http://www.dustdeputy.com/index.htm.
From there I will install a ceiling mounted hose system with "drops" to above the various tools. The only thing I expect to take up floor space will be the can to collect the dust, droppings, etc.
I intend to include a couple of "floor inlets" that, when operating, I can use a push broom to push the sweepings into. The system will then suck it up to the collection can.