How far i sto far for the couple of days? - Glasgow is 85 miles from Gretna - first stop in th ereal world. Loch Lomond and the National Park is north of Glasgow on A82 - take you 45 mins. Go left at Tarbert to follow road round to then at T-junction go north on A 816 to Oban for a circular route around to Crianlarich. Take you back to Loch Lomond and home. Easy route and lots to see.
O try a south on the A816 to Crinan and Campbeltown. All great sceneery and lots of B&B's all the way round on either route, and both would give a taste of the scenery and food and brilliant area....Loch Fyne Oyster bar comes to mind for a wee snackette......
Alternative - after Gretna, stay on A74M and then take A701 to Moffat (stop at the Moffat Toffee Shop and enjoy....) and tourist route through the Borders to Edinburgh. North then over bridge (�1 toll) to the East Neul of Fife and take in the coast and St Andrews. Tons of things to see - stop at choice of accommodation to suit - back to the VisitScotland website may be best - and not too trying on the driving if the weather closes in and covers the hills.
For a really great stay, go to:
http://www.farmstayuk.co.uk and enter the region of Scotland you want and stay on a farm in the area - great value, location and food.....hope this helps..