Dual exhaust systems were the normal OEM setup for the earlier years, but I am not sure about the 90's.
The manifolds of choice should be "long tube" as they increase torque, but I have read good things about Thorley's Tri-Y too.
If you really want to be sure and have a great quality, long lasting, bolt on system, then Banks is the way to go. At a price tho!
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!