I'm sure you can't really go wrong with any of those choices as far as sound quality goes since they're much talked about/revered products.
You might as well cross the Burson off your list since there is no optical in. One of the reasons I didn't end up going with it (that and I'm not a fan of stepped anntenuators).
The one thing that turned me away from Schiit was the lack of flexibility with their products.
One input, no preamps, etc. That may or may not be a factor. If not, then this may be a product for you.
The HDP and DACmini both offer optical in and flexibility. I guess at this point it comes down to reading impressions of the HDP and/or DACmini and the 701s.
It's also a bit nice that the HDP is cheaper than all of the above, but like I said, make sure you read impressions to make sure it's the sound you want and to make sure the 701s are driven properly (which it should be).






