Groomsmen attire

You'll be fine with the groomsmen in white shirts with dusty blue ties. I do recommend checking with David's Bridal to see if they have ties in that color, since different companies can have different shades of the same color. But I'm doing dusty blue for my wedding and the groomsmen are in charcoal, with white shirts, black ties, and cognac shoes and belt. And then my FH is in a dark blue suit, white shirt, black tie, and cognac shoes and belt.

I too am doing dusty blue! Such a beautiful color. I actually think white shirts would be a lot better than dusty blue ones. That would go great with a navy tie.

White shirts are considered more formal than blue but honestly every combo you've suggested sounds great. White shirts are the best choice even if your dress is ivory.

Grey tie with a grey suit and white shirt is very Cary Grant - see, for example, North by Northwest and To Catch a Thief.

If you're interested in this sort of thing, grey-ish ties in patterns like the ones below (shepherd's check, houndstooth, or glen plaid) are considered especially classic for weddings.

https://www.styleforum.net/threads/what-is-a-wedding-tie.216530/