I find it is best to keep the number of colors on a new house to two. Body, (linen white) and trim (Mocha)
In the railing, I would paint the rail cap (the part your hand touches) trim color, the ballusters (or pickets, depending on what part of the country you're from) body color, and the bottom rail the trim color.
I would do all of that in latex paint. If you insist on stain, I like semi-transparent Cuprinol, and you can have it tinted to just about any color.
Have fun and watch out for drips. Paint from the top down. Several light coats are better than one really thick one.