Scotland in my future?

[Randy]

My lovely bride has suggested going to Scotland for our August vacation this year. The party is my wife, 16yr boy, 17yr old girl, me. Also travelling with us is another adult, and possibly two more fellows. We are partial to hiking, history, nature/birdwatching, music of all sorts, tasting beers and whisky, but we are willing to try anything twice. Who knows, maybe I might be able to find a kilt or two for sale while there. A layover in Iceland has been suggested. Due to scheduling the only window availible is August 19th-27th.
I am asking what are the must do/see things in Scotland?