Quoted from ABJoeGreg,
If you feel good with the exercise you are doing, it may be right for you. Some Type A people fall into the Explorer Genotype and need a bit more strenuous exercise...
For the supplement - since I don't know what type knee issues you are encountering, my recommendation is to look at the Protocol list and determine which fit your situation and look at those for proper supplement usage:
You are correct with your Genotype choices: Type A can be Teacher, Warrior, and Explorer. The best diet is SWAMI - takes more personal input, provides very specific to you diet information.