Hello, are you in chat today?
First, let me say how wonderful it is that you are considering organ donation. It's an amazing gesture!
To answer your first question, there is no age limit on being a "live organ donor". People as old as 75 years of age have been known to donate organs. Therefore, as long as your organs are healthy, you should have no problem donating them.
Also, it is possible to donate a kidney, or even a lung (yes you may live with just one) to someone who needs it. If you had someone in mind, you could do that, or you could donate one as a "nondirected donation"
If you would like more information on live organ donation, please check out this website: http://www.kidney.org/transplantation/livingdonors/infoqa.cfm
If I have answered your questions, I would appreciate it if you hit the GREEN ACCEPT button so that I am credited with my response. If you have any further questions, please let me know. Thank you, XXXXX XXXXX luck!