You're exactly right, music is much more difficult to get sounding good than HT. For a receiver, I'd recommend Arcam. I've heard the $1500-$3500 Pioneer, Rotel, Integra, Denon, Sony, Yamaha, NAD and B&K receivers. The Rotel, B&K & NAD all sounded okay for music. But the Arcam AVR300 was the only 1 to sound good. It has a true 170 watt per channel rating for the front 2 channels in music, 100 watt x 5 for surround. Instead of the usual over-stated Japanese ratings for a very narrow band. I owned the $3300 Integra DSP 9.1 (I got 1 for a good price) with bells & whistles out the wazzoo, but it was terrible for music, and even home theater had a dull, muffled sound. My Rotel 1066 and Parasound 2205A combo for $3000 absolutely blew the Integra away. And I even prefer the Arcam sound over that combo. It's not as dynamic, won't play as loud, but it seems to pull out details from music and movies better, and has a warm, almost nostalgic sound. The 1066 has a kind of digital, analytical sound on music. I'd put the Arcam up against any $1500 pre-amp processor.
But for really good 2 channel music you have to go to a dedicated 2 channel pre in my opinion. No processor or receiver in your price range, or even 5 times as much can match a good $2000+ 2 channel pre. I've owned the $5000 AVP, $6500 AVP2 and $4500 Integra RC7 pre-amp processors, with the Integra being my favorite. All well reviewed, but couldn't match an Audio Research LS16 on music in a side-by-side demo. Which was $3000 new, selling for around $1800 now. And I've heard the Ayre K-5x up against the $10,000 Lexicon and Theta Casablana II, and for $7000 less I thought it cleanly beat them both on music. With the Casablanca being jaw-dropping for movies.
Most $2000 new 2 channel pre-amps will have HT pass-through for movies. So if you really want a step-up, I recommend you research $2000+ when new, 2 channel pre-amps. Otherwise, maybe pickup an Arcam AVR100 or 200 for less than $1000. Which is almost stealing at that price.
Good luck.