Best Rolex Dealer in London

[Wools]

Me and my Wife are having a long weekend away in London a week from now and I want to try on a few Rolex's that I've had my eye on. Specifically, the Submariner, the Submariner Date and the Explorer II.

Does anyone have any recommendations for the best Shop or Dealer (I know there's an outlet in Harrods) in London that they have used or have heard great things about? Our Hotel is in Mayfair so any dealers around that location would be best.

Also, as I've only started getting into nice watches recently, what's the protocol or is it bad form to go into a Watch shop but have no intention of buying at that moment in time? I would be buying my Rolex next year but if I love the shop and people, I would honour their customer service and would go back their to buy it from the Man or Woman who showed me the original timepieces.

Many thanks for any recommendations!