From what you describe you want in sonics with your associated equipment - you can't go wrong with the Unico. I owned one for quite some time (no Underwood mods - just NOS Mullard tubes) and it easily bested many out there. It will give you the smooth/liquid highs accurately and mids that have the warmth from the tube input. You can actually "fine tune" the amount of warmth, extension, etc. depending on what input tubes you use. If and most likely when I put together a second system that will be my integrated of choice. It is an incredible unit, and for the price I wouldn't look back.
Good luck on your search.
Good luck on your search.