First thing I'd do is return those Monster HDMI cables because you probably paid a premium price for them and can get just as good of cables for a lot less. As long as they are Certified High Speed HDMI cables from someone like Monoprice, MediaBridge, BlueJeans, etc you'll get the same performance.
Follow what ever break in procedures are suggested for your plasma and then just use the user controls that are available to you to see if you can adjust it to you liking. Some sets are pretty close to rec.709 out of the box and you may have to only make a few minor adjustments. If not, I'd get a disk such as the free AVS HD709 disk or one of the other commercial ones (WoW, DVE, etc) and learn how to adjust your set for brightness, contrast, sharpness, aspect, color, etc. You can try to find someone who has your set and is willing to share their settings for you but that more times than not doesn't work very well because component tolerances vary from set to set (even the exact same model) and your viewing environment is different.