I made this about 2 months ago using a megan muffler. Total was around 175 for the muffler and tubing and I made my own flange.
It has a 3'' inlet and a 3 1/2 out. Im going to eventually cut off the outlet and weld on a 3' outlet to make it even less noticeable.
Im guessing you dont want to pay $400+ for an aftermarket exhuast but theres Circuit sport if you decide to go that way
Or this one from megan with stock looking dual tips:
Megan Racing Type 2 Catback : S13 1989-94 240SX