I have a PS Audio DLIII w/ stage 3 Cullen mods and REALLY dig it... They go for around $1-1.2K on A'gon.
You could do a WHOLE lot worse than tkam's Northstar M192 MkII that he's unloading for $1K, IIRC. It's probably the best deal out there right now in this price range between the boards and A'gon. (just sold today)
If you're willing to stretch a bit more, Bel Canto DAC3 has a great rep (though I can't say I've heard it myself) for $1.675K on A'gon right now.
There's also a sleeper DAC on A'gon right now. In truth, I've been eyeing it myself. It's the Parasound D/AC 1100 going for $200. That DAC runs the PCM63K chip with a PCD100 digital filter. Well respected legacy DAC that is a TOTAL high performer.
On the more "musical" side of things, Electrocompaniet ECD-1's go for a bit over $1K on A'gon when you can catch them. They don't last though, so if you see one and you're wanting it... move fast!
EDIT: Oh, I just noticed your balanced output requirement. That narrows it down to the PSA DLIII, DAC3, and ECD1.