Food for Different Aged Felines?

I have two cats that are in two completely different stages of life. My Vinny is nearing 9 years old, and my Sherman just turned 1 year old. For the past few months since I got Sherman, I've been feeding them Purina Multi-Cat because Sherman's previous owner sent an 18-lb bag with me when I took him home. I fed Vinny Science Diet when I first got him last year because that's what he was arrived with, but thought it was way too expensive so I went with Purina One instead.

But now, I'm almost done with the bag of Purina and am not too sure what to do. I'd like to feed them something more nutritious yet inexpensive, but since they're also so far apart in age, what should I feed them so that they get the nutrients they need for their different stages of life? They're free-feeding dry food only cats, with maybe a can or two of wet food a week as a treat. Can I get a "senior" food for my Vinny and be okay that Sherman eats it, or an "adult" food and be okay that Vinny eats it? If I do go with the adult food, what happens when Vinny gets further into his "senior years" and Sherman is still a young adult?

Any suggestions would be much appreciated!

Hmm, I think some brands come in all life stages, I think Royan Canin may be one but I am unsure. Neither Purina or Science Diet or any good though. Royal Canin is better, but I am sure there are some really good options. Someone will hopefully be along shortly with suggestions.

One thing to remember too though, when you buy the better quality foods they are going to be much more expensive then your average, low quality purina, iams, science diet, meow mix, etc....

BUT cats who eat these better quality foods will fill up faster on the good ingredients and tend to eat less or less often. The food lasts longer and keeps the cat healthier which also means less expensive trips to the vet. Searching for new food can be exausting, but people here have some good ideas. Someone will post soon with some thoughts.

I would suggest looking at Chicken soup , Nutros max in hairball , Royal canin .... The first one is an all stage , the second has a good protein / fat ratio for a senior and young adults and the last one has various formulas .... Ideally you would feed a senior food which is fine for a young adult but being just above a kitten I would just look at foods with 30-33% protein if you older one is fine and has had a senior blood work up in the last six months