As an avvid backpacker, I'd like to offer this:
I prefer to use trail running shoes. There is no need for heady-duty support when your pack weight is under 30lbs (like mine). It is my opinion that "ankle support" is a misnomer, for the most part. Watch how you step, and appreciate how much better light shoes feel after a long day.
The most comfortable pair of shoes I own are a pair of Montrail Vitesse. I've got hundreds of miles on these babies, and their as comfy (with a set of "Superfeet") as the day I bought them. Buying shoes is a personal thing. Head to an outfitter with a BIG selection, and try a bunch out. Talk to other backpackers. Bring your pack with you and load it up. Walk up/down inclines in the store (a good store will have these) to make sure yourfeet don't slip. Slipping and moisture is what causes blisters.
Get a good pair of wool socks (I dig Thorlos, but that's just me).