Curious about how to go about making a custom SOPHIE and Charli xcx doll for the kids I babysit

I posted before about this but the kids I babysit (5 and 7) are currently obsessed with Charli XCX and SOPHIE because I mentioned once in passing I was going to see a Charli concert in a few months and lead them down a rabbit hole. One of their birthdays is soon and I wanted to make it extra special. These girls love barbies and even have one doll whose whole personality is that she goes to Charli concerts and time travels to see SOPHIE. I was wondering if anyone had suggestions for base dolls I could use to make their dreams come true for them? Specifically maybe a doll I could use that already has red hair so I don’t need to dye it for SOPHIE or one that comes with sunglasses for Charli and has her curls? I know no item at the store will be exact but I’m hoping to find something as similar as possible to the two so I can spend less time adjusting them to be identical and more time decorating the boxes and seeing their smile when they finally each get a doll of their idols. Thanks in advance for help. (PS: their current fav songs are lemonade and bounce so if anyone knows of any barbie playsets that have lemonade accessories or maybe a trampoline? That’s appreciated too.)