I use One Stop DIY for flavors and bottles and My Freedom Smokes for all the other goodies for DIY. MFS has a pretty good deal on a starter kit, but they are usually out of stock on a bunch of the items here lately. All you really need is a couple of 10mL graduated cylinders, a couple of syringes or pipettes, and some empty bottles. When you find a flavor or 2 you like, you can upgrade to 50mL or bigger cylinders or beakers. I'm mixing 100mL batches of a couple of flavors these days. If you are concerned with DA/AP, OSDIY clearly marks all the flavors with an asterisk if they contain diketones. They also have a couple of house flavorings that are super tasty and don't need to steep. I keep a bottle of their Blue Raspberry Slushie around at all times. It's awesome!