A plunge router with straight bit and circle cutting jig is about as
sharp and clean as any method you might try and better than most. I
use a Dewalt 621 router, a 1/2" straight bit, and a Jasper circle
cutting jig. I've cut numerous holes for dust collection using this
method. You can make your own circle cutting jig from a flat sheet
material like MDF, tempered hardboard or plywood. The method is
precise enough, that I don't think you need to cut all your holes
simultaneously. Most jigs work off a small pilot pin located at the
center. If you drill this pilot hole in all your stock simultaneously,
then cut your circles individually with the router, the holes will line
up with each other.

The small Jasper circle jig is available from Woodcraft. It has
settings for holes 1" to 7 1/2" in 1/16" increments.

Bob