Unless you have money to burn, I would not have a “two watch” collection that essentially had two variations of the same watch. I would pick one of the Speedmasters (whichever you prefer), then pick a nice diver or three-handler to alternate with it.
Regarding which of the two Speedmasters to get, I’d probably get the 321. More classic, more versatile. But that’s my style. I can see the appeal of the Snoopy, but it’s pricey for what i consider a novelty watch.