I always use AKU boots, but I imagine they wouldn't be technical, or robust enough for the altitude you'll be using them.
In snowdonia last Feb, a friend of mine bought with him a pair of Zamberlan boots which he said he bought in Canada in the 80's. I thought they looked old fashioned and uncomfortably heavy, but having since googled them, and seen them in various high end mountaineering shops, they would certainly be the next make on my list to try once my current boots are worn out.
http://www.zamberlan.com/index.php
Here's their site. I guess they're a bit more traditional than you're mondern mountaineering boots, but I like that.