I wouldn't do dark gray. While it is still being used, the trend now is swinging warmer, creamier to tapes and beiges.

Since everything is stainless, I like the hardware to stay in the same family.

I just got my cabinet order today so I am set with the cabinet colors and the quartz color

This is the color of the bottom cabinets and island with a stark white cabinet for the top cabinets

I have pulls and an island fixture in a soft brushed brass tone, but went with a brushed stainless faucet because I was worried that many of the faucets I looked at looked too orange. My thought (though I'm not a pro) is that your faucet can be a brushed stainless to match your sink, and your pulls can be a different finish. However pulls in a brushed stainless finish might fit better with a modern vibe. My advice is to look at inspiration pictures to see if you like a certain look better, and to order samples of the pulls you are interested in, in different finishes, and see what you think. Note that some places will only let you return them if the packages (plastic sleeves) are unopened.

I had to order and return several different styles of pulls before I found the ones I went with. It's worth the time and effort to get the look that makes you happy.

Champaign and brushed gold don't sound modern to me, but more of a traditional look. I'd go with polished chrome hardware.