You might want to try all organic/ all natural juice. I highly recommend Virgin Vapor.
Another one that I haven't tried yet, that offers all organic/ all natural is Vaperite. Both of these vendors have stellar reputations among those of us who can't take the artificial stuff without having bad physical reactions.
I started having terrible reactions to the chemicals and artificial sweetener/ flavorings with the 'mainstream' juices, but have had no problems at all with the juice from all-organic Virgin Vapor. Also, I can honestly say that Virgin Vapor has the best tasting juice I have ever had. Absolutely delicious and full of flavor! It even comes in glass bottles, instead of plastic.
Another thing you may want to consider is the poly-fill in many cartomizers. I use the Bud Sapphire cartos that don't have that material in them at all. They hold 1.5 mls of liquid, and are really easy to fill and use. The taste is clean, too, right off the bat.
I hope this helps!