I've been thinking hard lately about buying one kinda go to in case of emergency pistol. I've pretty much narrowed it down to Gen 4 21, HK Tac or 9SD and Sig. Possibly just keeping my G17 or Beretta 92 and getting a new barrel or a threaded barrel. So first question, I've seen before that 9mm is easier to suppress than .45acp, which I understand but is it enough difference to give up the beauty of the .45round? And what about the .40S&W? How's that go with a supressor? Another one is sights for use with a supressor. The kind I've seen suggested look almost like they're bolted ontop of existing sights. I mean I might be wrong but that's what it looked like. There has to be a better option. Finally, if I go with glock, is anything else necessary to do to them to make it work well?