First let me say that you have a beautiful frameset, so no matter what you choose to do, I know you'll have a beautiful bike.
I've had my Italian steel dressed out in several configurations. Here's a couple of pics with a black Swift, black tape, black housings:
Here's a couple with a white Concor saddle, white tape, white tires, and white cable housings:
And here's another in all black with a Selle Italia Flite saddle. This is the current configuration, and I have no plans to change anytime soon. My reasoning was that the white stuff looked nice, but was a real pain to keep clean (and the white stuff when it's dirty looks worse than anything IMO), and this bike is a rider. As for the Brooks Swift, I liked it, as I almost always do with Brooks saddles. But I have to admit, and maybe it's kind of petty, but I took it off because I felt like it's more appropriate to have an Italian racing saddle on this bike.
