which preamp to buy???

I am in the market to upgrade my current preamp ( Parasound P/HP 850), there are a few options here in my price range $500-600. My system consists of B&W 704's. Aragon 2004,Musical Fidelity V-Dac, Emotiva ERC-1 cd player. Cables are AQ King Cobra ic,Canare digital, and Paul Speltz's anti-cables (ic & speaker).
My room is large and on the bright side, lots of wood and windows, so I am looking for smoother highs and a better soundstage. I do not plan on needing a phono stage anytime soon.
Some of the pre's under consideration are the : Audio Research LS3B, PS Audio trio 2, Rotel 1090, Parasound Halo p3 and the Aragon 24k.
Any suggestions?
My room is large and on the bright side

I would consider treating the room instead of equipment.
Thanks Riley. I've already been thinking along those lines, but it's a problem...while it is our music room, it's also my wife's favorite room in the house...we have beautiful views which she doesn't want to block (hence no window treatments) and a very high wood ceiling...
I'm considering a folding screen with some absorbent material which I would put along the back wall and could be moved when I am not doing serious listening.
That being said, I still think a better preamp is necessary.
Slightly off-topic but I would replace that Canare coax posthaste. Just changed out mine and it's one of those times when you realize you were using a piece of flawed equipment.
Jult52: what did you replace it with? I would need something very reasonably priced?
I enjoyed my time with the Aragon 24k. Thats in your price range and would look cool with your Aragon amp. If you like tube sound try a CJ PV5 or similar vintage. Good luck
I'd take a 2c over a 3b. Either way, keep tubes and upgrades in mind.
Tbromgard: I was thinking similar thoughts, although I haven't been able to find out a whole lot about the Aragon...I don''t think that they were ever highly regarded for their pre's.
I used a 24k with outboard power supply with the 2004 amp and Apogee Centaur Minor speakers with very good results. I also used the PV5 as a pre amp in the same system. I actually preferred the sound of the PV5, but both pre amps were very good. As for positive reviews, I recall a few out there. If you are interested in the 24k, you can probably get one pretty cheap. If you dont like it, Im sure you can get what you paid for it since most of the depreciation has already occurred.
Conrad Johnson PV10 is your best bet. Add RCA 12au7 NOS tubes and you will be in audio heaven.
I would go with a BK Pro 10 MC. minimalist and I know where you can pick one up for $250
Thanks to all...I actually got a good deal on an Audio Research LS3b; and so far am very pleased with it.
Unfortunately, about a week or so after putting it in my system, my Aragon 2004 lost the right channel. A friend has it now for possible repair...if parts are available I'll have to see if it's worth repairing, or look into buying something else. Any ideas? There is a B&K ex442 avilable to me...