What home exercise equipment is best for over 50-65 yrs age range to loose weight ,gain muscle ,all over body muscle tone, flat stomach. would getting treadmill,elliptical,rowing machine or squat rowing machine or combination best ? never had any?

The best one is the one you will use. All exercise equipment has pros and cons, and if you have underlying health problems, do consult with your doctor to avoid making them worse. You want something you are motivated to use that is not likely to cause an injury. I have enjoyed all the machines you list. Currently am enjoying an interactive stationary bike with a subscription for classes and rides.

My recommendation is to move to the DASH DIET. My record patient weight loss is 140 lbs. Not only good for weight but also high BP, diabetes, preventing cancer, and feeling better. Get this specific book TJ Moore DASH Diet for Hypertension ISBN 9780743410076. Also get app Cronometer and track exercise and what you relay and drink. The best exercise is walking.