I have played with the PST for the past 3 years, but have experimented lots. In the Dunlop line I would say the 200 (closed pattern) or 200 Tour (heavier) are closest. The 400 Tour, is stiffer, has more power and really doesn't feel much like a PST.
I have just gotten a 200G and I suspect that this will be even closesr, but haven't had a chance to hit with it yet.
If you look outside of Dunlop, then I would say the IG Radical Pro and EZ Xi 98 have similar characteristics.