I think ceramics are better, remember reading about them on a forum somewhere
Most if not all are based on equal
Are we talking longtube manifolds (headers)? got any links? The best are pricy, and more expensive than standard to cat ones... I wouldnt as you get rid of the cats and come MOT your looking at a lot of cash to put the cats back in!
Am fitting RHD japanese manifolds so am sure they will be fine! But will update you
these are ceramic coated
http://cgi.ebay.com/ebaymotors/NISSAN-3 ... ccessories
this one is interesting as it claims long tube headers are better than short tube ones
http://cgi.ebay.com/ebaymotors/OBX-Long ... 3666wt_790
this is the full works
http://cgi.ebay.com/ebaymotors/Header-D ... 4259wt_944
I know we are talking about fleabay but the concept is interesting in principle