Saddle screws are .05" like you guessed as well. Take care with those as they strip out very easily... it's wise to detune the strings to take the tension off to prevent from stripping them out. I stripped out a set on one of my strats and i flipped them upside down and tapped a slot on the end of each one so i can adjust them with a small standard screw drive...
As for the hardware for your Gibson - Chrome is nickle... it's just plated and polished... Some places might call it just "nickle" and some places will call it "chrome" that's probably where you're getting the two confused. the only time that there might be a difference is when you can choose "brushed nickle"... which is a flat/non-shiny finish.
