I'm 6'2" and use the 182 cm Alpha 1s. If there was a size closer to 190 cm I would've gone for those because how short they feel is very noticeable (especially when you first try them out). I'm still happy with the 182s though.
As for the mounting question, I mounted mine at factory recommended -2.5cm. My last pair of skis (regular camber) were center mounted, but the tip rocker is longer than the tail rocker on the Alphas, making the factory recommended setting more centered on the ski's running surface.