Upgrading from B&W 601 S2 to ???

Looking for some expert advice, particularly on speakers.

Complete (hope not too boring) details: Am upgrading aging analog system, a process that began in the last few months when the old B&O Beogram 3000 went pffft for the third and last time after 22 years.

I bought a Rega P1 and the improvement was so instant and evident that I have, as you might predict, started Jonesing for other upgrades.

My old NAD 55-watt receiver lost its tuner awhile back so I have since picked up an Arcam Alpha 8 tuner on ebay. Then, as an experiment, I got an Arcam Alpha 8R integrated amp. Total spent: About $300.

I'm still a bit ambivalent about the amp swap. The Arcam, 50 watts, does sound more refined overall and definitely favors vocalists but the NAD seems punchier at moderate volume - particularly with rock or faster-paced jazz - tho the notes coarsen around the edges if you push it too far (Not sure i understand words like imaging enough to use them).

I do like the Arcam sound, however, and am hunting an 8P or 9P with the goal of bi-amping (other bi-amp suggestions welcome) current 601s or future speakers.

I have owned B&W 601s for a decade and, for their size and cost, always thought them capable, balanced and versatile with rock-folk-bebop mix that makes up bulk of my listening. Bass is limited and thumpy if pushed but that is not a huge concern since wife and daughter groan when things are cranked too high anyway. To me, the one place the 601s do not do so well on is classical. Instruments in complex passages tend to blend into mush. Sounds OK but clearly weaker than in other genres. Classical gets less play (maybe 10 percent) in the house so I have lived with it.

The "listening room" has big limitations. It's actually family room and is probably bad for optimal sound - about 10 wide by 20 long, with mexican tile floors, wood beam ceiling and windows across back and one side wall. There are two entry openings on other side wall. Speakers are a few feet from back 10-foot wall, toed in slightly but room is too narrow to move them from sidewalls. From the sofa far at the other end, however, the music still manages to make me pretty happy.

As you can see from my gear, I am strictly amateur and of modest means but do appreciate quality sound ...

That brings me to present question: I am trying to figure out if a speakers in the $400 to $800 a pair range, second-hand or new, would be worth bang for the buck. Or should I just stick with nice 601s and put money elsewhere - say, a better CD player? The Sony SCD-CE595 I have is a bargain-level multidisc but a few reviews say is good for money and can be modified to be very good for about same cost as new speakers.

I have focused more on floor-standers, figuring I have decent monitors already and that choice would add some mid-range. I have discovered a wonderful local hifi story but in my price range the auditioning options are limited. In a couple of years, I may be able to afford better at his shop. In the interim, I am poking around here and ebay trying to decide on reviews and rep, which makes me awfully nervous.

I understand this is a personal choice but any help/advice appreciated. I guess I am worried most about over-reaching for speakers my modest amp or room cannot get the most of.

My list so far from reviews and discussions. I have not any of them. Some clearly push my price ceiling, which has some give at upper end if a speaker was truly worth it:

* Rega R3 or R5 (love the turntable's simplicity and sound so guy says speakers follow suit; also the sidewoofer seems suited to rear wall placement).

* Epos 303: (Analog guru who sold me Rega and reviewers gush over ELS3 monitor but I am preassuming my 601s would be equal to those or better, perhaps incorrectly).

* Spendor s-5e (On the pricey side but people seem to thing very highly of this brand).

Others of interest: assorted 600 or 700 series B&Ws if I can find for right price, Tannoy S-10, Acarian Alon II, Monitor Audio Silver S6.

I did heard a pair of Tannoy Mercury F4s, which are very affordable. I liked the sound, really pulled out the guitar and banjo, but tone was bright to me and vocals got lost a bit. To my ear, different but not better than 601s.