A collection of Johnnie Walker like that needs a bottle of Green!
How do you like the Yamazaki Sherry Cask? Maybe you could post about it in my Japanese single malt thread?
Try to find a bottle of Hakushu, also from Suntory - completely different, and incredibly unique. From Nikka, if you can find it, Miyagikyou 10 and 15 are incredible too.