I'm not sure what exactly "leggings" refers to. I wear gators most of the time, which won't keep deep water from getting into your boots. If the water is deep enough that you can't cross the stream without getting water over the tops of the boots and consequently inside the boots, then your feet are going to get wet. In that situation, there are other options. You know it's not a sin to get your boots wet. I always carry a couple pairs of extra socks. After you cross the stream, take off your boots, wring out your socks and drain the water out of your boots. Put everything back on and wear your wet socks for 1/4 mile. This pumps the water out of your boots. Then change into your dry socks. Hang the wet socks on the outside of your pack to dry.
One time, when I knew that I had to cross a stream that would inundate my boots, I carried a pair of deck shoes. I changed into the shoes, crossed the stream, then changed back into my boots. I knew I was coming back the same way, so I hung the wet shoes on a tree and retrieved them on the return trip.
I've seen lightweight hip waders, with waterproof Nylon tops. That might be what you are referring to. But they are pretty expensive and I wouldn't want to leave them hanging on a tree.
BTW I always use Smartwool socks.
You may like Altama Maritime boots. Midsole doesn't get wet, water drain holes. Cordura. Dries remarkably fast. Durable, multi-surface/substrate and water use.
