I am soooooo sorry that my brain is so slow and could not think of an idea RIGHT AWAY. But on my way to work, I thought of an original play that might work...(that we could write).
And I think I incorporated a couple of your ideas too. It would be called "Eliza & Monica" and would go something like this (BTW, I haven't figured out the ending, but am thinking).
1. Eliza and Monica meet each other at work (I have different (and weird) ideas for how they meet each other, but don't have my notes w/me). Monica is the American girl and Eliza is the CRAZY english girl. She educates Monica about the way things are, because Monica is so totally lost about England.
2. Monica (yes, lots of potential Monica Lewinsky jokes, because everywhere I went in England tour guides always slipped in a Monica Lew. joke into their speech and maybe UK people think this is funny). So Monica goes without Eliza for once and meets this HANDSOME, BRIGHT, WONDERFUL, SEXY ENGLISH DUDE!!!!!! His name is Robbie (potential Robbie Williams jokes here, yes). He is the greatest.
3. Monica and Robbie are so in love, but she introduces Robbie to Eliza and they fall in love. Monica decides Robbie & Eliza are shallow and she doesn't need them for friends.
OK, this has to end happily (MAYBE), but I need to figure out the rest of the story. But I totally want to incorporate the American girl w/out a clue (which is kinda Bridget Jones-ish) and then have the nasty (but not too nasty) love triangle.
Let me know if you have any ideas on how you think this story could end. I am kind of building up the plot/outline right now just to see if this could be feasible.