Where do you get your DIY flavourings?

I know VapourEyes has quite a few, so I'll be checking them out soon. Usually I order through Juice Factory, but they're constantly out of koolada, dragon fruit, and heaps of other concentrates I'm trying to get. That and they only carry a few vendors. I'm just wondering where I can order a good variety of flavours since I'm still fairly new to DIY. Thanks in advance!