Never tune on the narrowband (factory o2 readings)...at that mod level you might consider learning how to tune and getting it done yourself that way you can tune on the fly due to weather changes and it isn't just a balls out tune you'd get for a 60* day...because when its 30* out...hello knock...and you'd have no way to fix it besides either not getting in the throttle or pulley'n up.
Second setup...I say 3.2". Why not smaller on a full-size IC/rockers/headers? Because I'd run that 3.2", on pump 93...and crank the timing on stock injectors and hope your IPW's don't run static.
