Gaia is pretty easy to find, most pharmacies have it and so do some of the large supermarkets now, I see.

For Aromababy, the best thing is to go to their website...they have a comprehensive list of stockists so you can pick one close to you. I don't know if it's just me but I just don't see it as often as I used to...that's why I've gone with Baby Sebamed for the moment (but I do use the Gaia detangler which is lovely, I've never used the Gaia shampoo).