Get fractional rubber heels. That way, you will keep your normal gait and not twist the shoes out of shape.
Replacement is no big deal; it's not the whole heel that gets changed-- just the bottom quarter-inch or so.
I've now found that G&G lasts are too flat across the lake/toe to fit me well, so that decision is pretty easy. Assuming, of course, that I don't want to spend even less to go bespoke in central Europe.
Nice stuff. I actually prefer the Brioni look on you, just because the jacket is a bit longer. Not that the Kiton is doing the Tom Ford thing, but the small shortening of the leg and greater margin of error elsewhere don't hurt.
Mercer. Just make sure you get small bodies for the collar size, and have them tapered in addition. Otherwise, you're getting the old classic Brooks fit, which can be a real tent.
Their best fabrics are bulletproof Oxfords and some poplins. Many of the softer luxury weaves I like less.