As far as XLR (balanced) or SE (single ended) goes.
Unless you plan to run 10's of meters of interconnect from the dac to the amp, single ended connection should sound better, as usually there are less electronics in the signal path.
Unfortunately many amps these days just have an added balanced opamp at the front end for XLR connection after which they go back to single ended, going single ended bypasses this opamp.
And the final connection to the speakers in almost most amps is single ended, just + signal, and - which is at ground potential.
Cheers George