and Ben Herr Performance manifolds are both solid products. The ported manifold is arguably the "best bang for your buck" performance mod available to the Road*.
The Nemesis was only offered in an Extended length. The Ben Herr is offered in Standard and Extended lengths.
The Nemesis uses o-rings to secure the manifold to the jugs and uses clamps to secure the manifold to the carb
. The Ben Herr uses gaskets to secure the manifold to the jugs and uses a rubber friction-fit gasket to secure the manifold to the carb.
DK's casting foundry went belly up recently, and as far as I know, they are still searching for a new casting foundry. I do not believe that they have any of the 99-03 or 04-up manifolds available for sale at this time. You MIGHT be able to find someone selling a used Nemesis, but then you would need to ask yourself, "Why would someone who HAD a Nemesis now be SELLING it?".
Ben Herr has had his own issues, but I believe he's up and running again, so his Standard and Extended ported manifolds are available.