7 is perhaps bit cheaper to run, 9 being more comfy so also bit heavier too.
Stay away from 2.0 litre motors, those are too small for what those cars weight, 9 will probably never rust if mudflaps are used and not crashed.
There is of course italian version of turbo, 2 litre 16 valve turbo with healthy hp readings, B204GT, but running costs might be bit high, lot of tires and petrol as it might be too 'sporty'.
7 is ok, but it is noisy and rather agricultural compared to 9 which still has some of those features, 7 is not very huge leap from 2, but 9 is quite different animal, steering seem to be not connected to wheels, however car seem to turn without much of feedback, speed is not felt like in earlier models, but very comfy.
I think that 9 series diesel was around 1500kg, that is net weight and weight really feels, it is not a sports car, don't know if petrol versions are better, but it is quite bit more than 7 or 2, early 343 weights about half from that?
There is one problem with turbo version with M90 transmission, it just begs bigger turbo, bigger cooler, more boost and proper engine management, I think it is not too difficult to get that 300 hp out from them, much more when touching internals? Bye bye fuel economy and welcome tyre seller, he is your 2nd best friend after petrol station man
