In EUROPE:
MacoDirect (Germay) also has a Tetenal Colortec© E-6 3-Bath Kit for 1 litres and for 5 litres (besides several C-41 kits).
See: http://www.macodirect.de/chemistry-c-765.html

I also found a French store called Labo Argentique. They seem to sell a lot of chemicals, but I have no experience with them. Anyone does? See:
http://www.labo-argentique.com//boutique/chimie-couleur-c-251.html?osCsid=b6e1b81bec08f28217705e4011d855c1

Prices seem to differ from store to store, so it is good to check for each product.