I cant remember who said it but they mentioned pulling shots into ice cube trays and freezing them. then bringing them out on a hot day add adding milk and some ice cream. I myself tried that and it works a treat. I have found that any sorts of beans work well, even those roasts (if you home roast) you do that dont turn out well. If your not looking for milk based drinks and you have a syphon beans like Ethiopian beans do well as they have a bit of a floral kick to them.
How ever i love milk (not by itself though) and i have found that iced coffee to be really nice.