There are some things that you may want to consider that you may have just not made clear in your post...
How are you going to transoport these decoys...meaning are you going to have a 4 wheeler to load them up? I say that because it may be easier to go light (not so many decoys) if you're going to have to haul everything a long ways...carrying your gun, shells, bag full of decoys and everything else you need can get pretty heavy pretty quick on a long walk...
We've hunted the last 3 years with the same decoys from Academy...the ones from bass pro, cabelas, and gander mountain sure are nice, but what we have now seems to work pretty well...people swear certain brands are more lifelike and work better, but our birds still continue to lock up pretty well...ive also heard those expensive decoys chip pretty easily and have to be repainted...depending on the terrain you hunt, those pretty decoys get just as muddy as the cheap ones
We usually have a mix of birds in our spread...some mallards...pintails...teal...all depends on the size of the area we are hunting...smaller areas we may just have teal decoys with a couple big ducks just to get their attention...
Ultimately, it depends on your budget...if you have the money, go for it!
Something else to think about decoys is how you rig them...this website (hopefully it works) shows a quick and easy way to transport, pick them up, and store them rather than winding the string and weight up around the bottom of the decoy...
http://www.txwaterfowler.com/html_pages/duck_hunting/texas_rigged_decoys/index.htm