My set up is pretty deep sounding, ill get some more recent sound clips together and send them your way. I'm not sure if it is the "deepest" out there, but it is deeper than all the HKS/Tanabe/Nismo's that i've heard. Next deepest was the EVO II

 

I have the Greddy Evo TT. Don't get that one. It sound alright, but the drone is horrible. I am really liking the Bassani, might switch for that one.

 

with 2000 i would buy a nice catback like a nismo or bassani with berk hfc's, then you would get that nice deep sound you are looking for.

 

didnt read any post in this thread but iv had 8 exhaust. So far deepest to me is AAM 3" TD exhaust with AAM 2.5" Test Pipes.

 

Headers, Test Pipes, AAM Single

 

My Cousins Set-up On His Z Is So Deep And Mean Sounding!!!
Helix Non-resonated Tp's/japtrix Y-pipe 3in/topspeed Pro1 3in!!!