My house is equipped with a 3hp Spencer air turbine industrial unit, 3 16" turbine wheels, bought it right at an auction.
That baby will suck a golf ball thru a garden hose, so naturally, my wife hates it. She'd rather play with her kenmore junk and ***** because she has to dust so often. Her eyesight doesn't let her watch the dust blow out the back of her Kenmore. She also really blows a gasket when the bag in her prescious Kenmore ruptures cause she forgot to change it, but she's dammed if she'll drag the BIG hose.
I point this all out because it's much cheaper and easier on your blood pressure to give any woman the vacuum she wants than it is to install a magnificent system and watch it sit idle.
Installing central vac systems doesn't take a lot of talent, if you can glue PVC pipe together, you can install one. Any system worth a dam uses 1 1/2" pipe and if your hose will be longer than 10' you want that to be 1 1/2 also.
Air driven carpet brushes don't operate well because the turbine to spin the brush will use at least 2 air horsepower. Electric to the vacuum port is easy to install.
You can get most of the parts from Power Flite,
www.powerflite.com, and you can also get just about any vacuum cleaner replacement part from them.
Central vac systems in a house are a HIGH markup item. If you will be installing in a 2 story house, roughing the plumbing in is easy when the walls are open, and you can do it yourself. For a single story house with an open basement the system can be put in any time.