GSX1000 and 1200 - latency-free side tone from XLR Mic?

[Teal Panda]

Researching DACS to move away from onboard audio for gaming, light commentary while making play videos and some general stuffing around.  

Unfortunately, it looks like many of the gamer-oriented DACS have a side-tone latency problem - and this would irritate me a lot.  My research indicates that the GSX1000 and the GSX1200 do this in hardware, so they have no perceptible latency.  Most headset mics don't sound great,

 

I already own:

• the Zoom h4n recorder that can supply 48 volt power, with integrated USB interface, and an AC power adapter for it
• an XLR condenser mic that needs 48 volt phantom power
• a few decent mid-range sets of headphones that I'm ok with

I would need to buy: 

• The DAC (preferably one that can do double-duty as a headphone amp for "mid range" headphones - nothing like 600 ohm) 
• A cable if I didn't already have an appropriate one in my box of tricks. 

My budget - I would prefer around USD$200, but can afford up to USD$350 if it really came down to it.

I'm thinking about two possibilities - could I:

1. Run a lead from the monitor out of the Zoom recorder to the GSX1000 - using the Zoom recorder's USB interface as the audio-source for my Windows microphone.  
2. Or, run a lead from the monitor out of the Zoom recorder to the GSX1200 Chat Link port - using the Zoom recorder's USB interface as the audio-source for my Windows microphone

In either approach I would effectively using the Sennheiser's sidetone capabilities to mix the Zoom recorder's monitor feed into my headphones with the game audio.

 

My questions for each of these possibilities:

1. It's pretty easy to select the Zoom's USB interface as the "recording device" in Windows.  Could I also mute the Windows Audio Playback of the Zoom microphone on my local machine? And, if the microphone input of the GSX1000 isn't selected as an input device in Windows, would I still be able to hear it on the hardware?
2. Does this Chat Link Port use a standard analogue line-level input? Or is it some kind of digital protocol?

 

I'm also open to other suggestions on how one might get "latency free" sidetone while using an XLR mic that requires 48 volt phantom power.