First off, what's your budget?
Wearing waders will keep you dry from the chest down. Pairing that with a good wading jacket should keep you dry. Keep in mind that with wading jackets you want to find one that has a good seal at the cuff to prevent water from running down your sleeve when you're fishing. Simms is supposedly the best for that but you're paying big bucks too. Or you could also wear a regular rain jacket so long as the cuffs seal well. As to waterproofness, it depends on the jacket. I have a wading jacket that is waterproof/breathable, but the cuffs don't seal that well so I don't wear it on days where it's pouring rain (like these last few days, for example). I have a Helly Hansen waterproof/breathable shell that I wear on really wet days and the cuffs seal really tight and it's kept me dry. It's also breathable so it's comfortable.