Nothing smaller than a series one Bridgeport on the Mill. You want MASS in a Mill for ridgid setups and so your not eating endmills. You can find a used Bridgeport or Quality clone like a Lagun, Webb, Index, or Tree for 2500-4000.
A lathe I would go no smaller than a 10" swing. You dont need a big spindle bore for pistol work nor a long bed. You can find a used Southbend, rockwell, leblond, or atlas for about 1-2000.