hello colette
I used to live in dumfries and galloway and tbh, I would not recommend Stranraer, it has a drug problem like lots of smallish coastal towns,poverty too, bit run down
Glasgow (I lived there in my twenties) has more to offer I reckon, culturally, etc, you will feel cut off, getting to Glasgow is such a hassle, Stranraer isn't pretty imho, but to move somewhere like that because you can get a reasonable sized house, do you wonder why houses are so cheap there? I wouldn't move anywhere that distance away from Glasgow and your friends for that reason alone, I could understand if you were moving for a job, but surely there is somewhere nearer you that might be less remote? if you did move there it would be almost impossible to afford to buy in somewhere like Glasgow if you had made a mistake, it won't be a great place for job prospects/promotion....
I also know someone who works in Stranraer, she despairs of getting anything in the shops there, often struggles to get nappies for her lo's and is generally never very complimentary about it.....
maybe you'll get more responses, good luck with your decision....