All these cars are really nice, but nothing lower than x35 obviously because of the torque.
E90 335i at least in my region is the car to avoid because reliability problems. I really like the way it looks, however.
M135i is real nice but then you can find everything right/wrong with it online. My own experiments is that, to carry an equal sized adult front and back, the maximum height is 1.73m. So the driver is 1.73m, the person sitting directly behind the drive at max is 1.73 m. This is my current car, but I stared at it for a very long time to like its exterior
I tried out my friend's M3 in a rainy day, and it is more predictable and the back end slides out easily. M135i and M3 will make you very happy in the mountains that's for sure, and both destroy tyres easily, har har.
I vote for M135i + LSD. How about a new/used Cayman S, does everything you want, but no back seat