Recommendation for Dac for streamer

Given that you have an ACS10, the D-03x seems pretty redundant.  You don't need a disc transport and although Luxman doesn't make a bad DAC, it's not like they have this sterling reputation for making incredible DACs. 

I would buy a separate DAC.  Given the quality of your gear, I might look a bit higher end.  Not sure what your budget is.  

In the $4500 - $6500 range, Audibyte HydraVox, Rockna Wavelight, Chord TT2, Bricasti M3, Holo May are all excellent but different.  Depending on if you prioritize soundstage and image vs detail retrieval and then if you want something brighter vs more neutral dictates the choice.  

At the next level up ($9K-$12K); Rockna Wavedream, Chord Dave, Bricasti M1, Weiss 501/502, MSB Discrete - there is very little compromise.  it is just how warm, neutral or bright you would like your sound profile to be.   

The Aurender is a great streamer. Looking at mostly the cost of the Luxman Transport / DAC I would also think given the rest of your system a single purpose DAC (not transport also). What about the LUXMAN - DA-06 DSD DAC. This seems to be more in line with the rest of your system. 

Really depends on what sound characteristics are most important to you.  DACs come in many flavors/types and there are a lot of very good ones out there these days so would help if you could narrow it down by sharing your sound preferences.