I think we have already covered this, but...
You will need a Nac112x, Naim Snaic lead, Naim FlatCap power supply for the 112x and a custom lead to go from the FlatCap to the Roksan to carry the signal.
But really, I wouldn't. Unless you have the LIII for free. And even then I'd sell it and go for a NAP150... Naim pre/power amps are really designed to work together.
Can I ask why you want to mix the two (without being awkward in any way - I'm just intrigued)?