A great idea but I doubt that you can pick up wooden crates as they were last used in the 70's. It's possible that there may be some on eBay but I doubt that they will be in GB.
Your idea about them standing upright is correct but if that much of a "fanatic" it's most likely that he won't use ice.
A possible idea would be to segregate the bottles by blend and malt and then subdivide the malts into their regions -Speyside. Highland, Lowland, Islay and the Islands [possibly have a separate section for the Islands] and Campbletown.
Whatever you do do not put bright lights in the cabinet as that will have a detrimental effect on the whiskies.
I hope he appeciates the trouble you're going to for him