Something with ankle support would be good i agree, if your just going out on a day hike trail runners suffice. However when your out for a few days and covering unknown terrian with a pack ankle support is good insurance. I have also noticed that my joints in my legs are less sore the next day when i wear boots.
Look for something lightweight. And skip the waterproofing, that will just add weight, and when it does get wet, it will take forever to dry.