The fact that she's not anime is irrelevant. Cosplay is not Japanese-exclusive.
I vote for bleach-blonde. That's what most of my dolls were. And I didn't see the white/yellow available for that wig.
And please do post pictures when you get the costume made; it sounds awesome!
Pre-production: Sweetie Belle (MLP: Friendship is Magic) 40%, Viera (FF Tactics Advance) 80%, Alice (Disney's Alice in Wonderland) 70%, Lenna (Final Fantasy V) 60%, Jennifer (Rule of Rose) 90%
Filming: Mikoto (Final Fantasy IX) 40%
Post-production: Jennifer (Rule of Rose), Pinkie Pie (MLP: FiM), Stephanie (LazyTown), Ty Lee (A:TLA)