I'm with everyone who says it should be RVD/Rey for the WHC title at ONS. Having a WWE belt decided on the show is something I'm against, but if it has to happen, let two ECW guys fight for it. Keep the WWE guys off the show this year, they're a needless distraction.
What happened to the original ECW belts? Well I have a couple of solid answers, and two "um...":
World Heavyweight Title: The belt was left in the possesion of Rhino when the company folded. Rhino has admitted to since selling the title on eBay.
TV Title: Was thrown down by Rhino at Guilty As Charged 2001 so that he could challenge and defeat The Sandman (a mix of shoot in the work here, as Rhino said the title didn't matter anymore because "we're not even on fucking TV anymore"). The belt however disappeared in the confusion that night, and has not been seen since (I'm sure it'll pop up on ebay some day, or some fan somewhere has it).
Tag Titles: Last held by Danny Doring and Roadkill, last I knew, they still had the belts in their possesion.
FTW title: Originally a TV title spray painted orange. That belt was retired, and probably discarded. An actual FTW title was made for Taz to carry later on in his reign, and was briefly held by Sabu. The belts were unified at ECW Living Dangerously '99. My assumption is that Taz was given possesion of the now purposeless FTW belt, and is still in possesion of it.
As far as replicas, a replica ECW World belt was made by WWE, and has been for sale on they're site since at least last year's ONS. It's a bit pricey though at about 100 plus dollars.