iamsexing
Welcome. The parish would appreciate you reciprocating the time and help we give you here with your tips to foreign visitors of your domestic market; what goes around comes around. Please also write reviews on here of any meetings.
There is a single dominant listing site in the UK already mentioned called Adultwork. In many ways this site UKP operates in a symbiotic relationship with AW although two are completely separate and many members here including me are critical of AW. It is the Microsoft of punting in the UK.
One of the many problems with Adultwork is that the search functions are very flakey, not least because they depend on the data the service providers put in. As a result if you specify a certain dress size or service and the service provider has not entered an appropriate response in the correct field you will miss her. So my concern about typing your criteria into AW is what you will be back will lose the vast majority of service providers who fit your criteria. I suspect that it is for this reason that Zeusthedoc advises as he does.
I understand you want to visit a UK girl. Zeusthedoc's advice is good; UKE will provide you a start in identifying English service providers that take your fancy. I will point out that you will pay a premium for a UK SP.
If you are flexible on this...
1) Depending on your price point review the site at House of Divine so you can establish a reasonably priced fall back position. Seasoned punters generally move on from HoD as it is a bit like McDonalds. I regard Magnito's post as definitive
https://www.ukpunting.com/index.php?topic=187369.0 so I am not recommending them, but they do provide a starting point and could be useful if other arrangements in the unpredictable London market go wrong.
2) On the wiki, check out Tontober. There are some very good providers in this list.
Good luck and please let us know how you get on.