Price range?
Heres what I would do:
Oversize Les Baer frame/slide
Heinie straight eight sights with the rear leg cut off and notch opened to .140"
dropped ejection port
Fitted SS match barrel, bar sto or Nowlin
GI recoil spring system
Ed brown thumb safety
S&A grip safety
STI carbon fiber trigger
hot shit ignition set of the 'smiths choice @ 3 pounds
flat mainspring housing with internal lanyard loop
dawson rail
dehorned
gunners grips
golf balls front and rear (you are familiar with that texturing, right?
EGW slide stop, no texturing on top, serrated bottom
Black-T
Thats my idea of a first class fighting arm. Leave the small parts to the smith. Things like hammer, sear, screws, plunger tube, choice of certain brands etc.
If you meant build it yourself, I'm sorry, I misread your post. I would not reccomend doing that. It is harder than it looks and more expensive than having one built.