The vast majority of research stuff online is sports related. There is some good pointers though if you look at taping vs mechanical supports for prevention of ankle injury as they pretty much all come down on the side of mechanical supports (which is basically what having a high leg boot is seeking to do). As mentioned above, strengthening the ankle through exercise is without a doubt the best place to start but that doesn't mean it should be the only route to take. It's also worth mentioning that one article espousing the value of the ASO Ankle brace (on a walking blog) does make the VERY valid point that no matter how good your boots are, if your gait means you are prone to ankle sprains or if you have a weak ankle from previous injury, NO walking boot is going to completely prevent further injury on its own. From a personal viewpoint I think it's worth remembering that walking boots and tactical boots have very different requirements in the way they will be used and it's entirely possible to go hiking in a good pair of trainers as long as you prepare your feet and joints for it first. There is no one "best boot" for everyone and people need to bear in mind when making recommendations that their feet are not the same as anyone else's and that the BEST boots are ones that fit properly.
If you're in any way concerned for the health of your lower extremities, go see a proper podiatrist that can analyse your gait and give good advice. I went through the NHS and ultimately ended up with custom orthotics that have been an absolute god send! (I have very high arches, I supinate and am prone to Plantar Fasciitis)