[Closed] Cycling Glasgow to Carlisle via the Aryshire coast.

Hi all
As part of my 50th year I've arranged for myself and several friends to get the train up to Glasgow on a Thursday night then Friday cycling down the coast to Stranraer area for stop over , then Saturday across to Carlisle area for a stop over then Sunday down to south Cumbria. I know loads of routes from Carlisle home but the first two legs are virgin territory, my plan is to hog the coast as I want to visit a small village called Dunure that I remember visiting many moons ago. Is the A77 from Turnberry cycle friendly or is it too busy, we want a craic as we ride whenever/wherever it is safe to do so. After Dunure would we be better heading across to the A713 and down to Newton Stewart or are there even quieter routes down through the Galloway Forest Park? Looked at the Sustran No 7 but this didn't look 100% road bike friendly and we are all on our "best summer" bikes. Also are there any must do gems in that area of Scotland ?Any help/advice very much appreciated. Basing it on 3x 90/100 mile days.Cheers John