I absolutely love that quilt!!! I have a magazine with that pattern and it's on my to do list...just not sure when it will make it to the top.
Do you have a LQS that sells variegated thread? You could take the top to the store and unwind a few feet of different colors and see how they look. There's so many colors, you probably have several choices. I don't think I'd go too light though.
A meandering pattern would be nice, either stippling or any other meander. I did try out the paper stuff, but I don't like that I can't see where I'm going. :) I draw patterns on sulky solvy with washable markers, pin it to the top and quilt thru that. It's clear so I can see what I'm doing. Then you cut away the bulky parts and the rest washes away. I love it!
Definitely practice before you start or you will likely be disappointed!