RE: decoys and calls
If you can tune a call decently then I'd look at a Haydels DR-85. A lot of them right out of the package are a bit too squeaky or nasally for my liking... but if you can adjust the reeds to your calling style then you can make that thing sound almost exactly like a hen mallard.
What you will find in a call, be it good or bad, depends a lot on your hunting style and your calling style. If you are hunting flooded timber, you don't want a super loud call... nor do you want a swamp bore timber call if you are hunting big open lakes/rivers.
As far as decoys go, as long as they don't shine I don't hardly think it matters. Putting them where the ducks want to be is much more important than having them look exactly like the real thing. I've shot a lot of ducks over some very sorry looking blocks in my life.