As far as stock vs stock on the turbos, not really sure.....
The "w" in HX35W means that it has a wastegated turbine housing. The later model HX35's have the wastegate acutator mounted to the compressor housing, the older style has the actuator mounted to the turbine housing. BTW, how much $$ for the HX35 that you're looking at? Which turbine housing does it have? (probably 12cm)
Sean