I have the Linksys one and it's great.
It is RJ-45.
If you are going to sharing a cable/dsl connection with it, then you can only hook up 4 computers.
You can get it for about $35 by having Staples.com match Onvia's price for it, then use a Staples coupon.
Edit: I mention Onvia instead of Buy.com to pricematch from because Oniva doesn't charge shipping, so Staples can't charge you shipping costs if you pricematch from Onvia.