Since whisky doesn't age in the bottle, your endeavor would be more appropriate with a case of wine.
However, if you want to do whisky, then I would recommend a vintage bottling of the Glenrothes. They bottle certain years' casks when they are ready to be bottled, not just when they are a certain age. This produces unique bottlings that will never be reproduced.
You can find a 1985 vintage right now if you look hard enough, which will be impossible to find a few years or more from now. I have one set back.
Another option would be to find a special edition bottling, but you never know if it will be worth your investment.
Buying a standard offering would be nearly pointless, as it could only get worse, and won't get any better. Standard offerings are blended by the distillery to be the same year after year, so there isn't much purpose having an older version of the same whisky.
Personally, I would either get a vintage, a single barrel, or a bottle of vintage port.
Last edited by jwise; 10-31-2011 at 03:53 AM.