I know for a fact that the HKS 3103-RT006 will fit. I have one on my Soarer, and my friend has the same piece on his MKIV.
Be careful though, alot of the pipes go all the way to the turbochargers on a Supra, deleting both the cats on that car. It will not fit any JDM cars.
But a "mid pipe" or the HKS one I just listed off will work. Fits perfectly.