CommScope 734 would be ideal. This cable is close to the same size of RG-6 and is good for 450 ft. runs. If the equipment is customer owned you may also need to change the line build out to compensate for the distance. Most DS-3 equipment is not usually set to run that far unless the provider knew at the time of installation. When you obtain the cable, be sure to inquire about connectors too as the core is larger than RG-6 also. Do not even attempt to run 735 cable )the smaller stuff) that distance, I have never seen the 735 run that distance even with the LBO set to maximum!! You can find more info on the net by searching 734A and 735A.