Given this history, it's pretty important that you get checked out by a doctor before embarking on an exercise program (if you haven't already done so.) That's the standard advice for anybody getting back into exercise but there may be certain exercises you should avoid because of the above or any other pre-existing conditions that you may have.
Technically, your age, your BMI => 30 (the pro's and cons of BMI notwithstanding) and the pre-existing condition that you have described are all risk factors that need to be managed.
By virtue of his young age, your son also falls into a 'special population' - specifically to weight training, the human skeleton is developing until the age of about 25 so lifting weights at too high an intensity before this age can last in permanent issues. So probably both of you are going to be lifting at more moderate intensities - the good news, that's probably what you would program for the muscle development that you are after rather than increasing strength.
Just on the supplements, I think you can get Vitality points for an annual consultation with a dietician (can't remember if you get a free consult or have to pay) - maybe you can do this with one who leans towards sport nutrition. But I will echo what others have said earlier that supplements are just that - making sure your diet has a sound foundation is most important.
Whey protein (without too much crap in it) is IMHO ok to help get additional protein on a daily basis at reasonable cost. I've also used BCAA drink before and during workouts which is supposed to help retaining muscle and some L-Glutamine to help with recovery. I have had high blood pressure since my mid-30's so pre-workouts and thermogenic fat burners are out for me and I probably wouldn't touch them anyway - pre-workouts in particular can be pretty hectic in terms of side effects.
Anyway, I hope that helps. Will get down from my soapbox now!
