Sony SCD-XA-5400 ES DAC Match

I have a Sony SCD-XA-5400 ES which I'm just crazy about. I've had it for three years and its my only source component. Is it possible to add a DAC to this unit and improve its sound. Someone at Audio-Advisor said I couldn't because its an SACD player(???)If yes, what would be some suggestions in the $1000 used range?

1. The digital (coax, optical) output is only from CDs, not SACDs.

2. The only HD digital output from SACD is via HDMI. I do not know of any HDMI-input DAC in that price-range, only prepros.
Have you heard of the Essence HDACC? I just ran into it tonight while surfing. It looks promising for my application but I've never read about it or heard about it up to now.
Looks like it does everything but I have no other knowledge of it.
I've run an HDMI out to my NAD M51 dac just for kicks. It converts the signal to PCM and outputs 176.4khz. I've A-B'd it against straight up analog outs. The 5400ES seems a bit more relaxed and natural as I guess it should.