I'll try to chime in here as I have some big feet as well. I typically wear a size 15 shoe but fit into a size 14 snowboard boot. I currently have a pair of size 14 Burton Rulers and size 14 Ride Jackson Boas. One tip is to see if you can fit into a smaller boot. I initially tried on size 15 boots but found that I actually fit much better into smaller boots. Now if you have to stick with the size 16 boots, I would say you should be ok without custom gear.
I currently have a NS Heritage X 163 and a NS Revolver 158. They both fit my feet well and with +15/-15 angles on my bindings, I have a minimum of overhang. I've also tried out my friends T.Rice 164 and it seemed to fit my feet as well which surprised me as its not a specific "wide" board.
Now as far as bindings go, I can only recommend what I have used. I have a pair of Ride Capos (XL), Ride Rodeos (XL), and a pair of Flow NXTs (XL). They all fit my feet very well. I've been curious to try out some other brands of bindings such as Rome and Union but am skeptical since they size things as L/XL. I would try those out in a store if you were interested in other brands. But I can attest that Ride XL and Flow XL fit my boots perfectly fine.