You can’t improve your striking game if you don’t practice kicks, punches, and elbows on a regular basis. You could always use a heavy bag for kickboxing and cardio boxing. The Body Action System X2 can also help you work on your game. It has a head pad for upper-cuts and hook and a torso pad with interactive targets for punches, kicks, and knees.
All pads can be adjusted up and down to accommodate taller and shorter people. You get 6 sandbags and instructional DVDs with your purchase. More information is available here.