I've been a lurker for a little while (took the CG step almost two months ago) but when I saw this thread, I thought I'd stop by and see if I can help.
It's not Glasgow, but I tried a few hairdressers in Edinburgh (I'm a 3a - I think).
(off Nicolson St, in the Old Town) is the only curly-hair salon in Edinburgh. I got my hair cut there once; the lady was lovely and very friendly, and she did cut my hair well so I had really bouncy curls. HOWEVER, she didn't really do what I asked (my friend had the same experience with a different hairdresser there) and even tried to give me a mullet! I had to go back to get the cut corrected - it was great for about 4 months but didn't grow out in a manageable way at all. I wouldn't recommend going there.
(in Cowgate, Old Town) isn't for curly hair, but the owner, Mary, is fantastic. I got a curly bob there about two months ago, and I'm really pleased with the result! She really looked at my hair before washing it to check curls and length, and it looks great! If you guys end up in Edinburgh one day, I really recommend going there. I paid about £35-£39 for the cut, which isn't too bad.
Hope it helps!