When I was in Glasgow last year I bought a braemar tweed at Hector Russel.
They had to ship it to me as they didn't have the size and colour that I wanted in Glasgow it had to come from Inverness. That said remember taht their are 3 different jacket names dependent on the buttons and cuff. I think that argylle and braemar are more common than the more simple look fo the crail. That said good luck on your quest in Edinburgh. Try Nicholsons on the royal mile.
Slainte David