I think if we went Buckner we stay with more 3-4 looks, and I don't see any reason to put Bosa as a Sam if we switch to a 4-3 he's obviously best as a DE, I think going with a 4-3 over could be realistic, but not the way your saying we should configure our personnel.
if we were to do it, say we got Bosa, he and Suggs would man the end positions Jernigan at 3t and Williams playing nose, but we don't have someone to play Sam, just because they are often on the LOS doesn't mean they don't have to drop into coverage, I think Leonard Floyd would make a great Sam/situational pass rusher but right now we don't have someone like that.
the team that comes to mind when I think of this defense is the 2013 Broncos, they had 2 3-4 DEs who were on the lighter side (285lbs) then a typical 4-3 DE with Phillips a good NT with Knighton and a beast Sam with Miller, Doom could probably match Phillips in the pass game and Suggs Bosa or Buckner could match Malik Jackson/Wolfe's role but we don't have a versatile guy like Miller.