Newbie - Which USED Amp & Preamp for under $2500


My preamp has seen better days and is sounding awful. My amp is pretty weak too. I have $2500 to spend and I need help. I've been looking at the following, any advice would help:

PREAMPS:
Audio Research SP17L Tube Preamp
Quad QC24
Arcam c30

AMPS:
Arcam PI monoblocks
Conrad Johnson MF 2250
Bel Canto Evo 200.2
Quad 99
Perraux 200P
Refurbished McCormack DNA 125

Below is my current setup. I plan on upgrading my speakers in the near future, so I'll want something that will work now and later:

Hafler 9130 amp (x2)
Adcom GTP 500 Preamp
B&W 602 series 3 Speakers

Thanks!
mmrump
Darkmoebius, Thanks, I have a couple questions...there is a Bryston 3B-ST available locally for $750. Otherwise there is a 4B-ST on Audiogon for $1350. Is the 3B something to consider, or is the 4B definitely worth the extra $$$?

I've heard a lot about the Mccormack DNA-125. Should I be concerned about the age of this amp?

In brief, what are the downsides to class d amps?

Would you recommend the Odyssey Stratos Extremes dual?:
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1260018001&/Odyssey-Stratos-Extremes-Dual-

Thanks, this is a HUGE help
The Cary IA write-ups seem very positive for jazz, blues, classical. Are there other recommendations for specific IA's in this price range? What is the benefit of IA's over separates? Thanks!
Audible Illusions M3A OR L2 are amazing pre's. I had the M3A and replaced it with an L2 for remote capability. Used pieces run approx. 800-1200. As far as amps go, I would go SS if you choose a tubed pre. Monarchy Audio amps are a very nice compliment to tubed pre's (for the most part).
Hello,

Big vote for Modwright SWL9.0 and a good SS amp. The IA route is not a bad way to go either ... maximize your buck. I like the flexibility of separates. If you like to play with upgrades from time to time you may want to go that route. I am looking at a Plinius SA-50 as a possible next upgrade for SS power. I'll keep my Modwright SWL 9.0 ... unless I go for the 36.5 (gulp).
The Bryston 2,3,4b-st amps are very solidstate like.No worries with McCormack,Steve is great to deal with.Stratos are also excellent amps,differing in the warmth department.
Must disagree with the AI-it burns thru tubes and they are slow-as-molasses on updates.