I love my Nait 3R especially powered from a Supercap.
A Nait 3 when I have heard one side by side with a 3R sort of sounded like bleh, tho.
I was surprised there was a difference but there it was...
The sound of Kan 1s would dominate heavily with either system and they'd perform equally well - or badly depending on your POV regarding the sound of Kan 1s.
Just considering a couple of options, would you go for Naim CD5I / NAIT 5I secondhand or a brand new Rega Apollo / Brio 3?
Either would be partnered with mk1 Kans.