I'd give some thought to how you'll be accessing the router in the Unisaw extension - from the front, the end? Then, survey the optional router fences available to see what best fits your routing needs, and that can be easily adapted to mount on the table extension. You'll probably want some sort of T-slot arrangement inset into the table to allow quick/easy removal of the router fence.
As to dust collection, again, lots of products. Delta makes several, and the cyclone-type dust collection systems seem to get high marks. You may want to put it in a separate, sound-dampening closet, though.