Totoherbs just put things a little confusingly that's all.
ALL production international spec STi's, version 7 and version 8, use the piston we show (also the short engine I described; hence the vehicle cost). International spec is everywhere in the world, other than Japan and North America. We know the JDM version 7 uses the same piston and we believe the version 8 does also.
As for the spare parts price of the cast U.S. spec STi piston, anyone who pays $1022.00 for a set is making a large mistake! The piston in our photo was purchased from Renick Subaru in L.A. a couple of months ago for $80 USD.
All the best.