I know... eventually all threads end up featuring the saintly 1911.. even glock forums constantly talk about 1911's But in a way they are like the AR in that everyone makes one and they can be customized so easily with so many parts available.
Lets start.. barrel and bushing... any match grade.
Trigger.. well.. the one it came with stupid.
Springs... Wolf is great but I think the Wilson Combat flat springs are the ticket. They are smaller in diameter so have to have the Wilson rod which is the two piece model.. They have been running up to 50k rounds without replacement.. I have had stock springs go 20k but I am sure it was battering my frame.
Magazines.. Mec gar is great.. Wilson is great. CM is great and the best deal.. Colt 7 round mags are really good.. I have a half dozen surplus Colt mags and they all work great.. one time I found a Colt mag in the wax paper.. had to be 40 years old or more and it was loaded... yep.. 7 rounds of 230 ball ammo. It ran flawlessly.
Sights.. eh... whatever.. I like the tritium cause it is really dull in the daytime outdoors... white dots annoy me.