Keep in mind most stains come in three different types clear or transparent, semi-transparent and solid or opaque.
I tend to like the look of the semi-transparent but each person had different tastes. There will be samples of each at the paint store or builders center.
There are also new products that are intended for a badly worn and neglected deck that claim to restore the surface. I haven’t used them and hear mixed reviews on how they work. Your deck is in good shape and won’t require that product so don’t let them sell you on it.
I have found you can get good products at both a builders center and also a paint store. The difference is mostly the knowledge of the people you will deal with. Big Box stores are hit or miss and you might walk up and get a kid right out of high school and never painted a thing in his life, or you might get the guy that’s retired from 40 years owning a painting company and is bored sitting around.
I also like the Behr products.