First of all, let me say that is one GORGEOUS quilt!! You've inspired me to dig out my S&W tool and some busy fabric and see if I get anything CLOSE to as beautiful as this!!
My thoughts on this would be the following:
1 - since you say you have become rather disenchanted with it, I'd do a panto to get it finished - otherwise, it will just sit there and piss you off.
2 - since it's for a child, again a panto or a meander would be best for ensuring that it's well-stitched, because I know it's going to be well-loved
3 - it's busy - VERY busy - so no matter what thread you use, the quilting would still fade into the background. So, yet again, a panto (preferably a curvy, curly or wavy one) or a meander will still be best for this.
With all that said, if you're still not happy with the top, I would be interested in buying it from you. You can PM me if you are still hating it.
I think it's absolutely BEAUTIFUL, GORGEOUS and AMAZING!
And you know what? I'll bet the little girl and her parents will think so too!!!