La Sportiva Nepal EVO GTX is my best choice.
In Europe it is considered a classic, the standard by which all others are judged.
It's been awhile since I got my mountaineering boots out of storage, so I just checked to make sure. Both pairs are Sportiva and I agree with chamois, they are IMHO the best option if you are going to spend much time hiking in snow.
You don't want those heavy Sportivas to be your only pair of boots. Also take a pair of unisulated, all leather hiking boots, as camp boots at night.
Don't forget your gaiters and lots of extra socks.
KC