Hey brother sorry I got to this thread so late but here's my opinion and comments.....
First Im impressed you're willing to change and take control of your life, props to you.... second you want to choose a program that targets all muscle fibers....GVT is a great example. If you can not do all 10 sets, to hell with it, 5 sets of 10 reps is sufficient in my opinion. Not certain what your diet or supplement arsonal look like, but you obviously have a good base to start with with over 20 years of powerlifting so it should take much to really get you lean and of very good size.
IF you could provide more detailed goals (size gains, strength gains, leaner look, etc *And dont tell me all of them ) Then myself and the other guru's will be more than happy to lay you out a program, etc.
Best of luck to you, YJ