Doing some research yourself would help, go on youtube and type in 2000 civic exhaust and pick which one you like the most. Brands like Skunk2, Apexi, etc are all good. s**t my buddy's 20$ ebay muffler still sounds pretty good for 20$ lol
skunk2 is over priced go to k2motor.com great i payed $280 for my stainless steal catback its 2.5 piping or if you dont like the fart can look go to yonaka.com its alittle louder then stock but can be driven with out waking up anyone and $70 more