If you're in Glasgow I'm pretty sure Caley Uni let non-Caley students use their gym. It's got a decent weights room according to my mates that use it.
I use Strathclyde Uni, but it's only open for graduates and Strathclyde Uni students. We've got two squat racks, plus an ER competition bench with a detachable bench, so in effect three squat racks. They also spent a fortune getting all Eleiko weights and dumbells a couple of years ago, literally tens of thousands of pounds just on new weights.