I use those plastic ammo boxes for my E callers. I've got a soft Ducks Unlimited bag for my FX3 FoxPro.
You can paint those plastic boxes in camo colors and they look pretty good IMHO.
I like them as the one's I have use a rubber "O" ring type material on the interface between the lid and the box top and it makes them almost water proof.
I have my Radio Shack Outdoor Speaker Horn and the Radio Shack Amp and my little MP3 player in one of these boxes and then my PM4 Johnny Stewart Caller in another. I put the rabbit decoy in with these devices as well as a woodpecker broken wing decoy.
I've got larger boxes like these that I use for my ammo and other supplies.