youre pretty much bang on. M35 denotes the Stagea chassis, it goes RS/RX, ARX, AXIS that are available in australia in 2.5L AWD turbo engines.
ARX had LSD and hicas from factory, both optional on RS and AXIS model. RX not being available for some reason.
except that Autech made the AXIS model. there is no autech model as such, however the aero selection models sometimes have autech stickers on the back. no idea why as they are manufactured by nissan
in the later model M35s there was a 350S which was a 6-speed manual RWD 3.5L model.