Haven't met too many Tundra owners huh?
I was going to recommend bigfoots for geese as well. My partner has them but this is the first year we've hunted over them so I wasn't sure on their durability. They definitely look good and ride well, and the paint doesn't seem to be an issue....and we just toss them in a standard decoy bag.
Regarding the slot bags, I honestly can't stand them. I'm in a hurry and I don't like to baby my gear. Duck hunting is hard enough without treating every bit of my gear as precious...that goes for the gun, the dekes, and everything else. I often walk in to spots as well so I need a bag that can fit on my back and is not bulky to carry. I like to wind em up, chuck em in, and get moving.
As far as species and variety, it's really going to depend on where you hunt and what species you are likely to encounter. You won't see geese in tight flooded timber, nor divers, but you will see woodies and mallards. You're less likely to see woodies on bigger water but you will see more mallards and blacks. You won't see woodies on the salt but you'll see plenty of blacks, buffleheads and a mix of just about everything else. Set up for the type of area you're hunting. It's good to have a decent variety so you can hunt a variety of areas, but that doesn't mean you put out every decoy you own.....
As for teal, I have a dozen, and I set a few hens out just because they're small and easy to carry, but really it won't matter. Teal decoy well to other decoys and often mix up other species. Most puddle ducks will...
I tend to put out a distinct cluster of black ducks, a separate small group of mallards, and sort of connect the two with a smaller cluster of both. I like to put the geese out further in the most visible area as they REALLY stand out and help with visibility. Divers are separated out as well for visibility and simply because I don't want to shoot the other decoys when they come in low and fast
A good thing to do is after the action has slowed and before you pick up your spread (or when you're retrieving a bird), take a far walk out and look back at your setup from a distance. You'll be surprised at how different things look from the birds' perspective and it will give you better ideas of how to set up next time. If you hunt with a buddy have him stay hidden as well...you'll be surprised just how visible he is sometimes and it will give you a better idea of proper concealment.