66 Dart, Sanderson Headers...what exhaust

Hi All

I've just purchased some Sanderson Headers. I want to know what you guys think I should do exhaust wise? I'm based in the UK, and have seen some of the twin pipe systems but can only find them for 67+. Does anyone know if I can use a 67 on a 66?
It would be great if I can get the full complete set for shipping ease etc.

Thanks
Steve