I think you are after more a dominant/kinky escort experience than a pure ProDomme from what you have mentioned.
I have in my time used the following agencies and escorts but I should point out not in a while. I now use Fet or just meet fun people in the London Fet Scene (see my review of Eva who I met via the Fet Scene and is now my staple go to domination/BDSM experiences):
De Sade Escorts:External Link/Members Only - she was amazing a few years ago. Will mix excellent domination and escort services
External Link/Members Only - saw her again a good few years ago. Sexy. Again she good mix of domination and escort services
Avis Babes:External Link/Members Only - again be a few years. Sexy german escort that knows her BDSM
If you are intrested in ProDomme then...
Direct ProDomme: in no particular order of preference
External Link/Members Only - HOT as fuck.
External Link/Members Only - not a loker but if you want some serious latex/rubber and/or meducal play this is your go to lady
External Link/Members Only - she is stunnimng and captivating with a mean streak
External Link/Members Only - a lesbian and seriously into her dark tantra. Excellent value and mixes sensual tantra (but no sex) with BDSM
External Link/Members Only - not for the faint hearted very similar to
External Link/Members Only in services
External Link/Members Only - Does tour London very occassionally. Seriously sexy, like seriously but dont be fooled by her looks. Really lovely lady too after the fun
External Link/Members Only - again very very occassionally in London. Read
External Link/Members Only above for look and style
The important thing is to discuss what you want to experiuence. Be open and honest with them. Tell them it is your first time, you are normally more dominant sexually but want to explore. Dont be perscrptive they will hate to be told I want X, Yand Z liek some tick box exercise. Just give them an idea about what interests you and importantly what does not.
Remember for the ProDommes and also for the BDSM escorts I have listed this is a world away from effing 50 Shades (of really shite) Grey. A book and Film that is nothing like the real deal I can tell you! You will not be able to shock them, they will probably want to push you and your limits, try to get you to open your mind to other things. My advise... just give them some ideas and then just go with a very open mind. They will have safe word policy so you can slow them down or stop them with that system. For most of the ProDommes above, if you 'think' you are dominant, I think you will will have your eyes opened to dominantion by meeting them ;-)
I want to session with
External Link/Members Only - when she next comes over to the UK and also am considering a trip just outside Paris to see
External Link/Members Only /
External Link/Members OnlyPM me for anything else.
Enjoy!