I picked up a pair of the Fly Maverik ATV/Dual Sport boots because they fit most of my criteria (especially the price). They do look a little goofy, I guess.
After an evening of walking around in them, I can report that they have absolutely no lateral ankle movement. They eventually warmed up and got more comfortable and I could walk relatively normally. I'm used to walking in snowboard boots, though. The construction quality is about $100. Some of the material is uneven, the stitching is kind of ugly, and the buckles are not super high quality. The plastic stink coming off them is strong, so they definitely need to air out. The sizing is just slightly large, but not so much you need the next size up, and they run a little bit wide (nice for wool socks). They don't fit tight to the calf, I guess because the tops hit below where the gastrocnemius starts to narrow down. With jeans inside them, they fit snug. My boot-cut Wranglers fit over the top ok.
I'll post an update after my first ride in them.