The character's hair does not look like it has an ashy tone to me. It looks like it does have golden tones. Unless you have pink tones in your skin, I wouldn't recommend ash blonde as it tends to wash out the skin, ala Kelly Clarkson & Lindsay Lohan. Too warm though, and it looks like a pumpkin, ala Lil' Kim!
I recently posted a message in another thread about how I lifted an Asian friend's black hair to carmel blonde (a warm dark blonde). She was a fair-medium skin tone and it worked well for her. Try going 1-2 shades lighter than this for a "Butterscotch" or "Champagne" blonde. The "Champage blonde" in my opinion is the best looking fake blonde you can have. It is definitely a light (NOT silverish like platinum), warm blonde... not too buttery though, and I've seen it work with many types of people no matter their skin tone. #88 is Wheat Blonde, and #16 is Honey Blonde, and #14 is Dark Blonde... almost like my friend's carmel color, and a less orange than the wig you have shown. The color charts are the same everywhere you go. I think #14 is your best bet, it will be a little darker than a traditional Champagne Blonde, but it will have the same desired affect.
Hope this helps, good luck in your search!
P.S.- I almost forgot to add that synthetic hair will always be darker than human hair of the same shade. The display colors are almost always of human hair. If you go synthetic, order one shade above what you normally would for human hair. I would also suggest checking out Ebay. They have some CHEEEAAP! wig vendors out there.