If you want to go for Rigol power supplies, I'ld recommend to get the DP832 for the +-15V, albeit at 3A max (in comparison to the 2A of the DP831 -- hope this will suffice) and have a separate DP811 for the 6.3V@10A (will supply up to 11A). I've got these two PSUs (besides some "el cheapos" and a few HP boat anchors) and have "improved" both. I guess this would be possible or the DP831 as well. I'm quite happy with the Rigol PSUs, I never expected that numeric input of the voltage/current would be so convenient, having had to turn knobs beforehand...
Btw, I never really got used to PSUs with coarse/fine adjustments, anytime prefer a single ten-turn pot (or digital keypad, even if its arranged ridiculously as on the DP8xx series
)!
Cheers,
Thomas