MG have a full-leather option for the ZR as well. You might be able to source some from somewhere like RoverBreakers, and you still get to keep the Monacos (to re-fit at time of sale, or sell on to make some money back)
I HAVE THE OE SPEC FULL LEATHER INTERIOR IN MY ZED.. ITS ALL BLACK LEATHER.. BOUGHT OFF OF EBAY FOR 500 QUID. I WAS TOLD WHEN I GOT MINE THAT IT WAS VERY RARE AS NOT MANY PEOPLE LIKE FULL LEATHER SEATS AS THEY DON'T BREATHE LIKE THE FABRIC CENTRES ON THE MONARCOS.. I THINK YOU'LL BE VERY LUCKY TO FIND ONE OF THESE INTERIORS ANYWHERE NOW AS I BELIEVE ROVER HAVE DISCONTINUED THEM. ALTHOUGH THEY MAY HAVE BROUGHT THEM BACK WITH THE NEW RANGES... GOOD LUCK !!