Pirate Queen: When in doubt I tend to go with what looks closest to the actual in-game sprites (http://ggxlol.highervoltage.net/baiken/)
. For Baiken I tend to prefer a darker, but somewhat muted pink.
What wig you go with depends on whether you're planning on giving it a haircut. You could probably get away with not cutting Celena at all and just tying it back, though the hair at the front might be a bit thin looking. If you're planning on cutting it, go with the longer Cher 951 because it gives the stylist a better opportunity cut it exactly the length you need.
If you go with the Cher 951: I find New Look's hot pink a little garish... and it looks too purple under flash lighting. Although it might be a little too red I kinda prefer Henna Red (http://www.cosworx.com/product_image.php?imageid=333)
If you go with Celena: Sepia's hotpink is pretty accurate and is what I would choose.