I am extremely interested in this topic and have read many times Sydneykid recommends the Tomei Poncams. I have also been advised, that the Tomei Poncams are only IN256/EX256 with 8.5mm Lift on both.
I'm not sure what sort of power figure you're after but these are not that big an improvement.
The alternative is the HKS Step 1's with IN256/EX264 with 8.8mm and 9.0mm Lift option, which also work with the VVT on the Series 1 and 2 GTS-t.
Can someone please comment on either of theses sets of cams?
Thanks Ken