Many fly fishing waders have "stocking feet", often neoprene to which you can add your own wading boots. These waders are super because you can get exactly the type of wading boots that you require according to the type of fly fishing you are planning to do. Some boots come with proper soles, like walking boots, great if you perform lots of walking along the river or across the hills to your favorite loch, others have combi soles or felt soles, each has their own advantages.
Additionally you can add your own studs for more grip on the rocks. These simply screw ino the sole of your wading boots.