Best 2 ch. Amp, for music, under $1k used


My current system consists of:
Classe ssp 25 pre-amp
Musical fidelity v-dac2 with Pangea p-100
Adcom gfa 545
Denon DVD 2900 used to play cd's
Paradigm studio 10 (planned future upgrade to studio 20's)

My question is: what amp would you recommend for my setup? I'm looking for better sound (fuller bass, better imaging, more power for higher volumes and more headroom etc). I'd like to keep it around $1,000, new or used.
By the way, there is a lexicon nt-312 for sale locally for $850. This amp is supposed to be the same as a Bryston 5b-st. Any input is greatly appreciated!
128x128b_limo
I only have experience with the McCormack DNA-1, but I just jumped to it from an Adcom GFA-545. The difference really is astounding. My 4-ohm Polk LSi9 speakers are completely transformed by its low-impedance capabilities. Got it used for a good bit less than $1K.

It's already in the hands of SMc Audio, for a Silver upgrade. Using the 545 in the interim. I miss the McCormack.
Bthogan, an adcom gfa 545 is the amp I am currently using so it's good to hear your thoughts on the DNA-1! Thanks!
B-limo, no problem. I love my GFA-545 - really. It opened my ears, and got me through a lot. But, as noted, the jump to the DNA-1 was unexpectedly amazing. In my case specifically, it's as if I got a new (much better) pair of speakers.
So I went into my local stereo shoptonight to pick up some interconnects and ended up leaving with a classe ca-150 to demo for a few days. A gentleman there is trying to sell it for $800. I'll let you know what I think of it after listening to it more, but my initial impressions are: more resolution and more bass.
The Classe CA-150 is a sweet amp. It should be several steps above your Adcom 545.