Tim
I don't want to put you off but after looking at her AW profile I would say you could do better, this of course is only my opinion and others may disagree. The main reason is basic profile, hidden feedback, has not logged on for a very long time, no photos, no UKP reviews to check against. Does not seem professional and imho at £175 you could do better.
First question probably of many, does it have to be an outcall for you or would you be happy visiting a WG in her own home/work place. (Remember if you invite a girl into your home, it might add to your pressure) If so how far are you willing to travel. It will open up your options. I'm talking about indies here so you would not have to see anyone else apart from the girl.
Do you have any particular services you must have ie Anal. Be honest and don't worry no one will judge you on here. Hey you might even want to wear a dress, you can get whatever you want that's what punting is about.