The RS3 8Y saloon was my Dream car as well I even ordered it in a Exclusive paint colour Porsche Riviera blue l had several build dates but all fell through so decided to patch it may get one when it's facelifted as for the Fiesta l have'nt a clue if it's got the B&O hopefully it has...l don't even know the price they are charging for the car we're on our 3rd sales person since we ordered a car from this dealership l had a Mk3 Focus ST3 back in 2013 loved it hated the electrical Gremlins though100%, if I could afford it I'd take the RS3.. especially in a saloon. Unfortunately not in the position just yet to get a car of that calibre. Bit of a dream car for me, would have to be in manual though.
You'll enjoy the ST though, mines a keeper until it has to go for a house purchase whenever that will be (not just yet....). I agree on the black, had 2 black cars, admittedly the second wasn't washed that well before I had it so was full of swirl marks, then I went molten orange and now green, white isn't my favourite either but imo better than black!
In regards to the spec, it's what Ford decided in order to build as many cars as they could, I think the one I ordered took around 9-10 months to get built, and that was after it got changed to a 5 door, which is a shame as people can't spec it to their liking anymore, but the only option you're missing in the B&O (unless that comes with Sync 3? Not entirely sure now since they changed the options)