At my day job, we have a large Morbidelli, that has a dust collection "manifold" with pneumatic valves to direct the vacuum to the required zones. One to the router, one to the drilling head, and one to the rake that unloads the table and cleans it at the same time.
I've thought about doing the same thing with mine, one for each spindle. I'll probably be using a 5" hose to the manifold, running from a Harbor Freight 2HP dust collector.

Gerry,  the 2hp blower from HF is not a bad choice for the money.  I got one delivered last week and was really disappointed with the condition I received it in.  The mounting fasteners you see in the pictures were total junk on mine.  One of them striped and loose, a couple more with the nuts off just laying inside the enclosure.  I replace all of them with some grade 8 fasteners.  About 30 minutes of work on it I was able to fire it up.  On the plus side mine runs really smooth (very well balanced) much to my surprise.  The suction is fairly decent.  I think that if you keep a small shoe footprint with hose selection to one of your routers it will do an ok job.  I don’t know if you have it or not but here is a coupon for the one I think you are talking about.

I am just thankfull of guys like Hood and Rich. You have to wonder how many guys this web site has helped. I don't know much but they sure make me look good.