Can't say I've worn them with waders, but I've had good luck with Smartwool socks. They're 100% merino wool, adn come in various sizes and thicknesses, so you 'll wind up with both a fitted, and a good fitting sock. A bit pricey, but my feet are grateful. Lots of folks swear by thorlos, but I haven't been blown away by them personally. Not bad, certainly better than the cheapo six packs from Roses or wherever, but not in the same league as the Smartwool socks I've had (and still have, discovered them a year and a half ago and haven't worn out the first pairs I got yet.).
You might also try some shirt pull downs if better socks don't get it done. Elastic straps that sort of button to the bottom of you shirt adn the top of your socks. Keeps you shirt tucked and your socks up. Simple friction fit button that I can't easily explain, but you'll immediately get once you see them. Ask Mens Wearhouse, or some other nice men's clothing place for them, they should know what you're talking about.
