Should I add a DAC ? Which one ? Never used one?

Hi

I recently switched to a multichannel but am trying to still focus on 2 channel as I have 1200+ Jazz CDs and 50+ SACDs. I have:

Magnepan 3.6r fronts
MG 1.6qr rears
phantom center
Velodyne HSG-15 just for HT.

Bel Canto Pre6 mch preamp
CAL Audio 2500 MCA (500x5 - which can be run in 2ch mode that is like having 2 monoblocks)

Arcam FMJ DV27A
Sony XA777ES
Sony C555ES for lighter listening

Interconnects: Kimber Hero from Pre to amp; Harmonic Tech Rainbow for DVD/DVD-A; Acoustic Zen Action 7 for SACD multi; Harmonic Tech Truthlink for analog CD; Acoustic Zen MCsq digital interconnects

Speaker: Fronts- Synergistic Research Alpha X2 Active (speakon to biwire bananas); rears Proco-Fatmax 8AWG (4 stranded 11AWG); 10 guage multistrand cooper wire between exsternal X-over and speakers and between tweeter attenuator.

I have a great 14 foot wide soundstage on my long wall with good transparency and detail from side to side, not as much in depth.

Would adding a DAC improve my redbook from eitherthe Arcam or XA777 ??
I have never used one and none of my local dealers have any of the ones I wanted to try.

I was considering a used version of one of the following:
Benchmark DAC
Bel Canto DAC2
MF TriVista 21 DAC (I use to have the MF TriVista Integrated and liked it a lot with the 3.6s)

Anyone have experience between any of these players ? I have 2 Acoustic Zen MCsq digital interconnects already. Any others I should consider. Would like to stay around ~1000 if it will improve my sources, could go up to ~2000. Would I be better off buying a dedicated CD player ????????????

Would like to improve transparency and detail further if possible - while still being musical with acoustic jazz small cobo material -- I collect trumpet players.

Thanks

AL