1 3/4 inch large flange muffler?

Iv just upgraded my Header from a 1 5/8 to 1 3/4 but Iv got no muffler for it, Can anyone recommend the best place to get one? I google, but only really coming up with US sites.

Or as an alternative does anyone know if I can just buy a 1 3/4 large flange that I can fabricate onto my old small flange 1 5/8 Muffler ?

Thanks in advance John