It depends what lengths you want to go to. The supersprint is the only one that offers manifolds currently, so if you plan to do those at a later date then it would be best to go for that system. I personally am not sure abotu the supersprint systems myself and have had bad experiences with their manifolds as they are made from a brittle mix of stainless and are prone to cracking......
If you just want a back box and/or centre pipe then you can go for the ragazzon which si the same one that autodelta use and re-brand as their own. But there is an alternative... I Have a CSC stainless rear box on mine. Nice deep tone, very well made and different from all the others
