I have found Purple Flame to offer a good range at good prices, with discounts for trade - just prove you are a qualified therapist to get trade prices. They do a range of preblended oils, the link follows:
http://www.purpleflame.co.uk/index.php?cPath=34&osCsid=545453b45a8929861eebd9ada7c4a695
We used some of these in our VTCT course, Ascension to relax but keeping mind alert, and Inner Calm for a more relaxing experience. Energise is lovely too: uplifitng and used on me when I volunteered as a case study. Delivery prompt, and people on phone friendly and helpful.
I have also bought sweet almond oil and much cheaper than many other sources I've looked at. They offer other oils too - I'm looking at coconut oil for IHM....