Same requirements as you, I went with a 75 dollar Atlas/Craftsman, circa 1950's, off of craigslist. Tightened the spindle, new higher grade bearings in the quill shaft gave me less than .002 thou runout at the chuck. It still turned too fast for gun work, so I added a jack shaft with a cone pulley between the motor pulley and the head pulley. Perfect, low rpm, quiet, tight, American made for under a 125 bucks. I would never attempt to mill with it of course, but it works well and is plenty accurate for drilling and tapping receivers.
