im about to custom fabricate an exhaust for my z... its gonna have a custom y-pipe with a 3 or 3.5 inch pipe from the y pipe to the HKS tip muffler! as straight as possible.. and im not sure if i should fabricate it myself or have it done at a muffler shop? do you guys know of any good muffler shops in the fremont/hayward/san jose area? can i use SS piping or will i need modular piping? anything else i may need? thanks for any help i can get!