What is the Best Product to Protect Oak Window Board Kitchens, doors, rails, stud, tables, chairs, stair cases, garden furniture etc... Find answers and ask questions here!

[Dragonfly]

I have a large bay window with a large wooden internal sill ( thinks it's oak) that requires some tlc. There are some water stains and a lot of cat scratches over it. I have lighltly hand sanded it to date which has improved it some what but need to add either a hard wax oil or some sort of other product to it to protect it ( I would love to stop the cat scratching it , but fear that's a losing battle) . I don't really want a hard shiny finish and don't want to lose the natural colour of the wood or the lovely grain , So not really sure about varnish ? The room has stripped back skirting and oak parquet which has some kind of water based polyurethane on it . Any suggestions would be greatly appreciated.