Look in the weapons area of the forums. There is a link for rubber ones and repro scabbards. They are actually pretty nice. Also if you lose one in the field, it's not so heart breaking as losing an origional piece of history. The other plus is using them in a reenactment to take out a German sentry.
Hmmm I'd like to get a rubber one but eventually get a real one for publics... Where should I look? Other than Ebay... sadly ebay only fits short term goals, and doesn't help me when I'm going to be looking for it a few years down the road.
They are expensive. E-bay, gun shows, and surplus stores are the only way to find these. WW2 reenactors forums sometimes will have one pop up for sale.
The molded ones sold on ebay are made of a soft resin and do hold a rough edge. Still they are very nice looking and look quite real in the field. I own a few of these myself although I rarely carry a fake one in the field myself I do on occassion.
As for the CHG Bylaws they restrict hand to hand but people come out with these fake knives and use them all the time. I'd be careful of the eBay ones. They could potentially hurt somebody if not used carefully since they are not made of soft rubber.