First, buy "Woodshop Dust Control" by Sandor Nagyszalanczy. This is a very comprehensive book that deals with just about every question you'll have (only $15.37 at amazon.com).
Anyway, I have the Veritas cyclone lid and it works great. But, you don't really need it so much for the table saw, but for the jointer and planer it is a must-have, IMO. Just the other day I was planing and jointing about
125 board feet of ash and I filled up a 30 gallon trash can 1.5 times. That's a lot of dust/shavings that I won't have to dump out of my dust collector.
I'm planning a ductwork system which will have a 5" main line with a 4" drop to the cyclone lid and a flex hose with quick disconnect for the tablesaw, jointer and planer. I'll then have more 5" main line with separate 4" drops for the lathe, chop saw, router (reduced to 2.5" at the cabinet), bandsaw and a floor sweep. I calculated static pressure drops, etc. for all of this and should be fine for my 1.5 hp Jet dust collector. The linear distance of the entire main line is only about 25 feet and each drop is about 6 feet, max. With blast gates, the air flow should be pretty good. Also, no matter what you read using PVC for the ductwork is fine, and you don't need to ground it. There is a good scientific evaluation of this problem somewhere on the net (DAGS) that makes it very clear.
Mike