Most of them are Catbacks,
you can get front/dump pipes separately
There are many brands available for BNR34,
If you want Titanium, you can get ARC, TRUST brands
We have best price on Apexi, you can get full stainless in canon or non-canon type
Other brands:
Fujitsubo
Blitz
HKS
Kakimoto also have nice catback (Single/Twin)
Latest catback with Titanium tip
Please let us know more info. so we know what sort of catback you are looking at.