Looking to better my redbook action....

If you can stretch you budget just a bit up to $2,000 or so, you can get a Resolution Audio Opus 21 cd player.
(I just picked one up for $2,200 delivered.) It is an incredible player. It brings me much closer to the music than either of my Sony ES players ever did. (Closer, but not quite to the level my Basis 2001 turntable does though!)
By the way, the lower priced used Opus's usually have the older transports which have a bit of a whine to them, not loud enough to hear while listening to music though. Also, the original remote did not have direct track access.
Both of these minor problems have been rectified in the later models. And R.A. does offer upgrades of both items. (Do a search on "Opus 21" and you will be amazed by the number of very positive responses!)

If you decide to go with the Benchmark DAC, (which is supposedly a great DAC), let me know, and I can sell you a Sony CDP-707ES cheap, which would make a great transport. (It is a 45 pound cd player. Sony knows how to make great transports for their cd players.) I have heard the Benchmark and it does sound good, but honestly not as good as my Opus 21.

My two cents worth anyway. Good Luck in your search.

Used Cal Audio Delta Transport with matching Sigma or Alpha DAC. The DAC has left/right output controls on the rear panel and is a good sounding unit. Both can be had for much less than a grand used when they are available.

You might look at the Quad CDP-99. It upsamples to 192 KHz, and has a volume-control output (controlled from the remote, I believe....check their website). Note that I do NOT own it (yet!), but every review I have read is very positive. Apparently a smooth, musical sounding unit (which may or may not be to some people's tastes).
Good luck on your quest.

thanks for the suggestions
I've looked at the Cal Audio Delta transports...but have not checked out the DACs. They have to be quite impressive to best my thoughts of the benchmark.

Take a look at the Stello DA220 DAC also.
Go here to read the recent Stello DA220 Review by Doug Schneider at Soundstage.com