Big difference in asking question if you say what speakers you have,what the sensitivity is,ohm load (all easy to look up) and how large your room is.Tubes are great and rule of thumb is you can double power rating versus a solid state.Muisc only or latter HT?Need to fill in blanks.But you have some good tips for a used unit for an 6-8 ohm 97-89db sens or better (limits speaker options but more sens opens up to lower cost to quality).Parasound,NAD,Adcom,Rotel is all on same plane but you could get a nice Creek integrated or Parasound and step up in quality.
Chazz
Chazz