The relationship you develop with the LBS is almost (if not more) important as the bike you buy.

I bought a commuter from my LBS, traded it in for a more expensive bike from them, and bought my kid a bike from them. Plus they maintain my beloved Waterford. Bikes may change, but my love for my LBS remains.

Just the idea that the other LBS is "reluctantly" ordering a bike in your size gives me the cooties. Ideally they should be "cheerfully" ordering a bike in your size. If they don't sell it to you, they will sell it to someone else.

Campy Mirage is low end Campy, which is still nothing to sneeze at. I have Campy Athena on one of my bikes. (roughtly equivalent to modern Campy Centaur) I find Campy to be much kinder to my hands than Shimano, but you may feel otherwise. If it were a choice between Campy Mirage and Shimano 105, I'd get the Mirage. Just my preference.

I also LOVE steel frames. (all my bikes are steel) So I am biased toward the Bianchi.

You really ought to try the Bianchi, just to see what it feels like. No harm in trying!