Hi Claudia,
I recently used the essential oil company - [link=http://www.eoco.org.uk]www.eoco.org.uk[/link] and they were very promt and had a good selection of base oils at good prices. I got organic sunflower oil and a cherry-stone filled ehat pillow (bliss!) from them. Give them a go!
Other than that I sometime use GW Baldwins - [link=http://www.baldwins.co.uk]www.baldwins.co.uk[/link] - they are also excellent, but didn't do sunflower oil!
Hope this helps!
Caty