The current understanding is that VG is probably a safer option than PG so you may as well go for that if you are home brewing. You can get it from the chemist/drug store. Look for bottles of food grade Glycerin BP, or look on ebay. The flavourings can be obtained online and from cake and candy stores. You need to be careful to avoid colouring, oil and sugar though. Lor Ann flavourings are quite highly rated, perform a google search and ye shall find. In the DIY
juice sub forum Kate, our resident expert, has many a handy suggestion and has posted a list of the OK Lor Ann flavours to use (i.e sugar/colour etc. free.) There is another US brand of flavourings too that i've heard referred to a lot, someone will let you know I'm sure. VG is super gloopy so you may want to dilute it a little with alcohol and/or distilled water. I've not gotten round to my experimentations yet as I'm still awaiting my flavourings but the recipe I have jotted down to try is as follows (I am personally aiming for the purest, simplest formula possible):
20% distilled water
10% vodka
10 - 20% Lor Ann flavouring (some are stronger than others)
60% glycerine