I've been using Yak drytrowsers that I picked up second hand a few years ago. Got them for the canoe but they just took over and are the only waterproofs I ever lift these days.
The leg seals are a footer but once they're on you have a gaiter-like seal over high boots.
Fancy a pair of Palm Vipers. Like the look of the 'normal' waistband and they're a nice cut.
[Edit - Sorry, didn't read the post properly, just seen the title and lurched right in. These aren't what you're after - they get chilly against the legs if you wear them on their own, you really wan't long-johns at least under them.]