I need to paint some doors from the house remodel. The doors are contractor grade and a light cream color. We want white. I have a couple of Spray-it guns, suction and gravity feeds and 3 need sizes (1.3, 1.5, and 1.X (don't remember) that came with the set. What needle is best for latex? How much thinning if any should I use? This is Valspar cheap paint.