Friend needs help

I have a close friend that wants to upgrade his stereo system.  He is old school and frugal.  Currently he has a Kenwood KA-501, which I bought in high school, many years ago, and gave to him after having it serviced.  He has Cerwin Vega speakers and B/W book shelves.  My question what would be a great integrated amp, with 3-5 inputs, a pre-out to add an amp down the road.  I am suggesting that he gets a WiiM Ultra streamer and get into the streaming game.  He is mostly a rock and roll guy.  He is leaving all of the decisions to me.