Hi CTJ, unfortunately you can’t use the same PSU on NDX2 and SN2.
The SN2 can be externally powered with a HicapDR or SupercapDR, the NDX2 can be externally powered with an XPSDR or a PS555DR, so each required a different box.
I did hear the NDX2/SN2 without power supplies at a show last year and it was a fantastic system. Much as I love my Nova PMC 25.23 system, I’d expect the NDX2/SN2 to be a significant uplift.
I’d think about running them both bare to start, then think about power supplies if you find something lacking, they’re a fine combination as a 2 box rig.
I did demo the NDX2 bare and with Xpsdr and 555ps. Its a fine player with no power supply and many people will be happy with the SQ. For those that want to upgrade its a nice uplift in SQ with a more authorative delivery. I was surprised how good the Xpsdr was, to my ears you get 70-80% of what the 555ps delivers for just over half the price.