as far as a black finish for your gun goes, Robar would be my choice. im only slightly biased.... my RC-1911 commander came in yesterday, and my Robar/Vang Comp 870 came in this morning!
i would elect to have Robar finish the barrel, barrel bushing, and internal parts with NP3. the slide and frame i would do in matte or satin Roguard (your preference- one is dull, one is shiny).
the Roguard has held up well on my duty 1911's, and on my Colt M4.
the NP3 is a silver color- its nickel teflon electroless plating. its really awesome stuff- it basically makes my Springfield MC Operator run without lube, without malfunctions for 1400 rounds (yes, i tested it in a week long instructor development class).
i know Robbie has been working on a black chrome as well, but im not sure where it is at right now.
either way, its a company i trust, and recommend to my friends.