GHG, Final Approach, Game winner...best to worst in that order. I own some of each. I usually only use 12-15 dekes, never more than 3 dozen. Sometimes we bring out a mojo too. I hunt mainly flooded rice stubble fields. On the other hand, my uncle hunts a large lake and never uses less than 100 dekes. Number depends on the area. I have mainly mallards, teals, and a few woodies and pintail. I'd say start with 2-3 dozen and see what you need to fix.
I would only buy the top brand and grade dekes if you are serious about it. We bought 5 doz. of the great buys earlier this year, just on a whim for they were cheap. Thats exactly what they were!!!! CHEAP!!! Out of the 5 doz. we bought, we have already trash canned 15 of them for they started leaking within a short season of use!!! We had some start taking on water the first time out!!!!! We bought them more or less for fill in on our larger spreads, never again. We will just spend the money and buy the top brand and grade and go from there.
Its better to just have a few really good decoys than a whole big bunch of crappy ones.
Hunting where you will likely be in SWVA... you probably are either going to hunt farm ponds or fast moving rivers and streams (some of these streams can produce totally amazing waterfowl hunting if you do your homework).
For those streams... all you need is 6-12 mallards (thats half a dozen to a full dozen). Doesn't take a migration flight worth of decoys to kill ducks when they are coming in groups usually not bigger than 5-7 with pairs and singles much more common. Use short strings and heavy weights to hold in the current... or if you have an abundance of baseball sized stones in your hunting area... make use of what you have. The best decoy weight is the one you don't have to carry up and down a steep slope getting to and from the river.
I still think that for a production decoy... you cannot beat a G&H... ride good, look good, tough a finish as you'll likely find.
For farm ponds or shoreline hunting, you still don't need a whole big bunch... make it 10-18 decoys tops (I still find I do as good or better with 3-7 decoys... even late in the year). You might want to look into some full body geese or even full body ducks if you have a gentle slope to a grass field such as in a cow pasture... think about what you see while you ride around scouting... and duplicate it.
__________________ You get what you put in, and people get what they deserve. - Kid Rock