UPDATE:
So after deciding to buy the OP, I strut into the local Rolex Boutique looking for the black dial OP 39. Unfortunately they, or any Rolex dealers in London for that matter didn't have a single piece in stock; thus I ask to be notified when one comes in.
I got the call 2 weeks ago and was seriously excited to finally get the chance to buy one.
Guess what I saw when I checked out the OP display?
They thought I had been referring to the white dial OP rather than the black dial I was after (despite stressing the fact that I didn't want the white dial at the time). The person who took down my request adamantly denied that I asked for the black dial and that I was mistaken. We chalked it down to miscommunication in the end. Another OP 39mm would take at least a month.
After looking over the boutique, only seeing PM day-dates laden with diamonds and listening to the SA rambling about how Rolex was the best; I decided enough was enough and walked out, never to return.
I knew it wouldn't be easy/quick getting a Rolex, but if that's how it works then I'll be happy to stick with Omega.