I was researching this a few days ago as well, and found some articles that said this is not considered wrong from a design standpoint. It sounded like it was more acceptable to mix finishes now, and some people prefer the not so matchy look anyway. I was curious because I have 3 rooms that flow together and I have brushed nickel in two rooms. In the 3rd room I wanted to put in a ORB light. I think it will work fine. I actually just replaced the windows with ORB double curtain rods (and these flow through two rooms). I also read that if you can add at least a couple pieces in that particular finish it will look even better.... so I felt having the curtain rods and the light would make it work, but I think even without, it's ok. Buy what you love, that is most important!

Is there a reason to buy the hardware before cabinets and counters are installed... then you can buy a sample of orb and nickel (... or, and chrome) hardware you like, and hold them up to your cabinets in your kitchen to select the finish you like best with your other choices? we spent a week or two at the very end of our remodel opening the drawers and doors from the edges (without handles/knobs/hardware), while we ordered samples, picked our final hardware from the samples, then waited for the whole kitchen hardware order to be delivered. It was not a big deal to use the kitchen with bare doors for that time...

the finishes are fine[if that's what you like]. However I think the dimension and shape of the hardware in the kitchen ,[ in this picture ] are not great with your specifics. Keep the gold hardware, if you desire.....but at least reduce the pull size: generally seek a softer/different scale/shape. These are too modern, and others are probably available. there are more warmer finishes to choose from, which means more configurations.

Yes, no one can look at both and take the time to be picky about it lol. You will be the ones who notice things more than anyone. And after the dust settles most of the time you wont even think about it anymore. Side note I dont think you need contrast on your cabinet pulls, a brushed brass would be really pretty with bronze..just a thought.