My first ever legit kit came from Heartfire Henna*, but I didn't know that until later. She was packaging them for a groovy mama catalog. Then I learned the hard lesson of trying to make henna paste from the 'henna' from the health food store -until I finally connected up with an online community of henna artists.
It's true there is a LOT of yucky stuff that people are trying to pass off as henna (like those cones from the grocery store with the brightly printed foils). So where do you get the good stuff?
Many of the established henna artists do sell: Hiral Henna, Sarahenna Seattle, Henna Lounge, and more. And actually ordering paste from any of these women is a good way to go.
In the last 6 years, I've ordered from just about everyone and been completely happy.
Henna Sooq - the glass syringe, plastic syringes & plant based hair products
Artistic Adornment - henna raw materials and ebooks
Henna Lounge - henna paste, Nud tattoos
Sarah Henna Seattle - powders and paste
Hiral Henna - henna powder
Henna Muse - paste, powder and other goodies
*Heartfire Henna - Rebecca has closed her henna business and gone wandering.