If you plan on charging boutique rates, then your brand name / domain name MUST say you're worth it. People should be half convinced even before they click to view your site.

In terms of name branding, you can do better than any of those competing sites you mentioned. A good name will bring you additional business and pay for itself over time.

I can help you identify the right property and obtain it. Honestly, it doesn't need to cost you a fortune either. Last month I sold TheGym.net for the price of 3 1/3 of your sessions. If you had purchased that domain, I'm sure it would have brought you many more sessions than that. Just an example.