There's an Australian cheddar they sell around here that claims 7 years, but it's not consistent from wheel to wheel, so we don't get it that often. Since everyone here has a lactose problem we love the aged cheddars ~ minimum 9 months!
Goat's milk and mare's milk cheddars are also locally available and I pick up half pound blocks several times a year.
I love saganaki, which sounds Japanese, but is actually a Greek dish. Most Greek restaurants use Kasseri cheese because it’s pretty easy to get. However, I had it once made with Kefalotyri cheese (I think it was the Greek Isles in Chicago) and that is the only way to go. You talk about trying to find a good cheddar, try finding a local source for Kefalotyri. I found one store in NYC and one in Cincinnati, but none in Indy.