The Rockwell is ~600 pounds, the Clausing ~300 pounds. The Rockwell is R8, the Clausing is Morse Taper #2. A used Rockwell, Clausing, or small Bridgeport in reasonable condition are all good choices, as is a new Enco knee mill. Expect to pay $1200 ~ $2400. Be warned that the 4" Kurt vice costs too much, and the 6" is too big