Mine are very simple brushed steel - no finial. I wanted the to just disappear. All hardware in my house us polished brass - older, very traditional house.

Once you have the actual curtain, and the mounting hardware is in place, you could try one of each if desired. Borrow a black rod from the next room, and try a gold style as well. Black would repeat your chair color and bring more contrast. However, gold would provide a little bling, and won't look as heavy against a light drape and wall. The white and gold balloons in the photo look good, and give some idea of how that combo might infuse a little life. Whichever you choose, I'd find a way to add a bit of color the dining space to break up all brown wood. Perhaps painting the mirror a fun color? Or switching out the white lampshades for a colorful shade. A table runner is another easy fix. If your budget allowed, you could do a more colorful rug, and also a size larger.

Can youy post at least one pic showing the room and the drapes.I think a silver rod is best to make the grommets sort of disappear but I need to see the space. One thing i will metion with white drapery IMo you need 3x the width of the rod to keep them from looking like sheets.

Would need to see the room and the finishes. But it depends if you want to have the rods stand out or disappear. Black rods, especially with light colored curtains, will draw the eye. If that is the only dark element in the room you may prefer a lighter color.