Obviously, what you need is something in the alpine touring, or randonée, lineup. As you've no doubt already learned, these boots fall somewhere between a plastic mountaineering boot and an alpine ski boot—they're stiffer than the former, softer than the latter, and allow the user to adjust the forward angle of the boot. A good example: the Garmont G-Ride ($499; www.garmontusa.com). Three thicknesses of shell material give you stiffness where it's needed, and save weight. And, you can adjust the angle of the shell. Still, these boots are not light—they weigh close to eight pounds a pair. Given your desired parameters, I'm hard-pressed to see you all that happy in them on the Sierra Haute Route, a 38-mile jaunt across some of California's most mountainous terrain. But that is the type of boot many people on the route wear, along with beefy telemark boots such as the Scarpa T2 ($479; www.scarpa-us.com). The T2 is lighter and more flexible than the G-Ride, and I must say it's a surprising boot—even if you can't telemark, you can do a pretty good impression of a parallel turn while they're on.
Of course, I certainly wouldn't sign off by recommending you carry two pairs of boots—one for hiking, one for skiing. I'd go with the G-Rides, and enjoy their good ski-ability.
Check out last year's Outside Holiday Gift Guide for more drool-worthy backcountry goods.