Hi, Big Licks. April stood me up 3 years ago, so she's off my hotlist although if you do get to meet her, she should deliver. Flaky, though. Dear, too. £130 plus £40 for 'extras' such as BDSM or anal. Seriously?
Genuine BDSM providers in Glasgow are Ella Anais, Eva XrX and Real Sub Girl. I've met this last one and keep going back, but she's hard to get hold of. Real deal, though. As you say, not many out there; has to be a lifestyle choice, something they genuinely like, because nobody is going to take severe discipline just for money. Unless desperate, of course!
Edinburgh boasts Estella Edinburgh and Emily Rose 2194. The former, apparently, is amazing. Both are on my to do list.
Are you sure this is the route you want to go down? Will you know what to do on the day? Suggest you read up on the subject before taking the plunge. I've a couple of years experience and am still learning...