Agreed on the HP all-in-one. I got mine as part of a package, substituted a larger LCD screen, and got a very nice Presario. He'll want a state of the art computer, though.
Ditto also on separate TV from monitor. There are too many times he'll want to surf and watch TV at the same time.
I just bought a HP Pavilion dv8330us Notebook; it's wonderful; complete TV capture/cable/LCD package; Lightscribe DVD and CD burner.
I just love it.
I'd go with the HP 3310 or 3320, too; the 3310 scans slides now!