I'm sure a lot of guy's would like to see Medford box.
Try power movement with-in a 4 to 6 rep range. You will build all the stamina (endurance & strength) from boxing drill's and lap work. No need for high rep. Squats mainly, because everyone gets their punching power from the feet up through the legs, hips and waist area. Power starts from the floor. Include GoodMornings for the lower back and the important hams for that leg power. DB pressing, see saw or together, overhead, which insures each arm/shoulder gets equal work and balance. Flat or inclines are not great exercises for pure punching power. The clean a jerk can be a key exercise for any sport. Do them. Any weight work done should be somewhat quick, with explosive power in mind. Good Luck and have aspirins handy in your gym bag.