I don't know if they're still going but two cracking Scots beers I remember were Maclays in Alloa and Belhaven in Dunbar. Just Googled them...sadly Maclay's closed in 2001....Belhaven open but owned by Greene King.
I'm not a beer drinker mate. Lager is my tipple. Ive heard of Maclays and we used to be sponsored by Belhaven. Yeah Belhaven Brewery is in or about Edinburgh. I'm afraid Youngers and McEwans has the beer market sewn up here in Scotlant