Have you considered verigated thread? Think with your batiks, it would blend really nice.

Beings I don't know what you're comfortable with on the quilting front, it's hard to suggest something.
If it's easy/simple you're shooting for, maybe a "X" in each square?

I would use something in the gold family, would not be as obvious if the quilting is a bit wonky. Or a variegated. Btw, Lovely color combo - great job!!

I would go with a variegted King Tut

Your quilt is gorgeous. My vote is for varigated thread on the front.

I'm not going to be of help with thread color, but I just wanted to say that your quilt is beautiful. You did a fantastic job!

No help here but had to tell you your color choices are wonderful and your quilt is so very gorgeous! You did an excellent job on it! I'm impressed!!!!

I would use a dull gold colour. Locally there is a LAQ who does outstanding work and I find I'm drawn to the quilts with the gold thread, it looks so rich.

Beautiful job! I would use brown in the bobbin to match the back. On the top, I would use a varigated thread, with either the green or the gold. There might even be one that would have some of all 3 colors in it. The reason for varigated is in case some of the thread pulled through from bottom to top.

Or if you wanted to do stitch in the ditch, match the top thread to the block, and use brown for the bobbin.