Advice needed building a system over time???

I'm new to AudiogoN, but happy to have found it. Long back, I got a taste for HiFi, but then had a very long hiatus. Always dreamt of the killer system, but other priorities reared their heads. About 7 years ago I bought some gear to drive the speakers in the ceiling throughout my house, without too much concern. Ended up with ROTEL separates which I even used to watch TV, again with the speakers that were in the cieling. Finally got a 5.1 home theater system which satisfies my needs using an integrated amp and MK speakers - I consider watching a movie a passive listening event and if it sounds pretty good I'm happy. It does.

So I had these ROTEL parts sitting around and decided to buy some speakers for them, to dedicate a room for active listening. At first the room was going to be a small space ~14 x 14, so I thought some stand mounted speakers would be best for that small space. I purchased some Usher BE718's that I thought sounded great. Apparently many reviewers have thought the same. My thoughts were to get a good sounding speaker at a reasonable price, then build up my components around them, finally getting something along the lines of Wilson Sophia 2s or Watt/Puppys.

Maybe not the best logic in system design. The room, however, changed. The acoustics in that room were not good, and the WAF (wife acceptance factor) limited anything I could do in terms of acoustic treatments, so I moved my audio room to a "bonus" room that is roughly 17 x 23. The Ushers still sound great the bigger room can handle more volume which seems to make the speakers even better.

Given I have a ROTEL pre- and power amp, with a ROTEL 5 CD changer, what would you all recommend as the first piece to invest in when moving to class-A or reference components.

Buy the way, long back I had an Audio Research tube pre-amp mated to a GAS "Son of Ampzilla" and I see ARC is alive and well (though recently acquired). Their gear seems to get tremendous reviews and I have a soft-spot for ARC. I plan to audition the Ref CD player and Pre-amp soon. I've also heard some great SS gear like Parasound HALO amp, T&A gear too. I listen to classical (my great great uncle was Antonin Dvorak) and a little bit of rock, Dylan, Mark Knopfler, Van Morrison, Norah Jones - broad range but no HipHop, metal, etc. I like musical sounds and sweet sounding vocals. I tend to dislike jazz when it gets too wierd.

So where would you spend your first upgrade $$ ???