There is a Heym 600 Nitro for sale right now in the US. Not sure what you get them for over there but might be worth a look. It is on gunsamerica.com .

As far as your comments regarding the material between the barrels... Are you sure they weren't talking about a Blaser?

Merkel, Heym and Chapuis are all good choices from Europe. Pick whichever one feels the best to you and your wallet.