Vic, have a look at Bill Pentz web site,
Dust Collection Research - Home
It's the most comprehensive place for dust control for small workshop anywhere on the web.
Bill is over the pond, but the same rules apply no matter what country it's from.
The most important thing to remember is if you are putting in ducting to feed all machines or are you just providing it for one machine. The airflow for the ducting needs to be right to prevent dust build up and the risk of fire.
The Vacuume units are good but limit you to airflow, the cyclone efficiency will be effected with how much airflow you put through it as well.
The wood chip units are also good but they don't protect you from the PM 10 and below. That's why they say it's no good to collect dust. So you need to change the collection method to protect you by fitting a cartridge filter or install a 100mm cyclone unit.
Prob not much help to your original question, but it's all down to your finances and what system you want to install.