1 kidney?

I am 54 years old, have always been serious about weightlifting and have been doing it on and off for 20 years. I have been steadily lifting since the first of this year and have firmed up quite a bit but want to go to the next level. I donated a kidney about three years ago and am interested in starting a cycle. My son recently started a cycle and he is happy with the beginnings stages of his growth and strength. I weigh 205 on a 6'1" frame and probably have about 20 percent body fat. I'd like to put on another 20 lbs. or so of muscle and cut down on my bf. Would going on a cycle be too dangerous for me? If not, what would be a recommended stack? Thanks.

Talk to your Doctor. I doubt there is anyone here qualified to answer a question like that with the possibility of such serious consequences.

Yeah man, when you have a unique medical condition you especially need to be evaluated by your physician. I have no prior or existing medical conditions ( that I know of anyway ) save for 3 or 4 allergies.
I consult my doc pre, during and post cycle. Then at least you will have 1 qualified opinion about the risks you have, are or will be taking.