I am looking at getting a S/A Mil-Spec and over time I will add/replace parts.  I figure while I am under-way removing any machine marks and stuff should help pass the time.  Basically, this gun would be one of those long term projects, where I would buy parts over time and eventually send the gun off to have the front strap checkered, barrel fitted, trigger tuned, finish and a reliability check.  Anyway, Extractors; is there one brand that is more reliable, stronger or better than the other?  Such as, the Wilson's or the Ed Brown or would the factory extractor do so long as it is in tune?  

The only extractors I use in my 1911s are Wilson Bulletproof extractors. If one breaks and I've never had one do so yet, Wilson will replace it for free.

The Wilson, Caspian, or EGW. will work just fine, you might look in to a decent slide stop also, EGW is probably the best one out there.

Wilson Bulletproof....VERY GOOD STUFF.