1) The heaviest AR-X Four version weighs 1710kg. Goes down from there to 1550kg for the RWD 2.5L 250RS.
2) It was 3.0L till 2004 when the 3.5L VQ35DE was introduced to the Stagea (finally).
3) No! No manual for you Stagea people! It's a shopping/family car! If you think the VQ35DE is a 'Skyline/Fairlady Z' engine, then think again! It's also in the ElGrand people mover van... talk about versatile.
4) Yes, 4WD is offered for all capacities (2.5, 3.0 and 3.5) in varying trim levels.
5) New they're between $30,000 and $40,000 in Japan.
6) Only if you get me to answer all these questions then *don't* get an M35
An old colleague of mine in Japan had an M35, and while it was only the 2.5L 250RX, he had the 'AXIS' M35 kit and wheels on it (AXIS is one of Nissans optional parts divisions, as is 'Own') and it looked the goods. Pity it was AT.