Hmm wonder if I should hold off on this one and have my buddy do something else on Wednesday. Unless he's confident he can pull it off.
personally, if you want your tattoo to look like that, i would ask your buddy to show you previous work where he did it. i wouldnt just trust him to say "oh ya, i can do it!".
In London? ..... Maybe Matty at True Love.... Or even Sean at Hangar 18.
If I recall Sean is (or used to be) into graffiti so he could probably pull it off. I think Matty has a new school style and might be into it as well. I haven't looked at his stuff for awhile now though.