DD has asian/black caribbean/white heritage and her hair is thick, loose curls with a tendency to be dry and get matted. We don't have a huge range of options here and she is currently using Shea Moisture Jamaican Black Castor Oil shampoo and conditioner. She will be moving to London which has much harder water than we have here, which she knows doesn't work all that well with her current products. However, on the upside, there is a much wider range of products available. Could I have some recommendations of where to start so that she doesn't have to buy and test every brand? Thanks in advance.