You need a 5" 1911 to get the knock down power you desire.
Im somewhat dubious about this statement. If you have close to a 5" barrel, go with 230 grain; when closer to or less than a 4" barrel, try using 185 or 200/200+P. Out of my 4" XD, I like the Gold Dot LE 200+P JHP, but find that the Federal LE 185s "handle" better.
Now, back to the OPs dilemma...
I like the 9mm for its capacity potential (somewhat defeated however when dealing with many compact variants), relatively light recoil and the fact that 9mm rounds are relatively inexpensive compared to most. But, when comparing round to round, I prefer the .45 ACP as I truly believe it has superior "stopping" power vs. the 9mm; Notice I said "stopping" power...not "killing" power.
Now, its true that a hit with a 9mm weapon is better than a miss with a .45 ACP weapon. But, this saying applies to almost any situation really, regardless of caliber. However, assuming the necessary level of skill, a solid hit with a .45 ACP would instill a bit more confidence (for myself at least) vs. a solid hit when using a 9mm. This increases by a certain percentage when .45 ACP +P loads enter the equation.
Now, there is the .357 Magnum (full house 125 grain) round to consider as an equally effective man-stopper (not to mention the .44 Mag). But, for maximum stopping power out of a handgun, while still maintaining necessary control for rapid firing, I believe the .45 ACP to be among the best..if not
the best. If all else fails, I then gravitate towards the 12 ga. shotgun. But, this weapon is not always the most "practical" choice, regardless of its effectiveness.
In terms of capacity (for HD), anything above 8-10 rounds is something I consider mute as I generally keep more than one loaded mag. Besides, if a close range, violent encounter cannot be assuaged within 10 rounds, I can most likely consider myself on the bad end of things at that point.
Also, as has been mentioned before, I think .45 ACP is simply much more fun to shoot vs. the 9mm.
With all of this in mind, to answer you "order of things" question, I would go .45 ACP, 9mm. .44 Mag. My order is only based on effectiveness combined with control, rather than focusing on a particular round or its capacity potential. I would have chosen the .44 Mag as my second choice but I feel that, while certainly powerful, the control just is not there (for me at least) when using full house loads, thus rendering its overall effectiveness (practically speaking) as less than ideal. Of course, I am merely speaking of "typical" HD ranges and thus, considering the most "effective" and "practical" weapon out of these 3 which would accommodate such a range variable.