With regard to painting your calipers red, I would personally take off the calipers and the hangers and have them shot blasted to remove all the debris then blown over with an air gun to remove excess dust, get some thinners or panel wipe to de grease them and then get them painted
the key is in the preparation, ive seen so many cars that look really botched as they have been wire brushed for 5mins and had a tin of paint sprayed on and it looks all nasty after a week as it starts peeling off
im a firm believer if a jobs worth doing its worth doing well