Oil is not hard to get. Its legal to buy and shyt. I have never bought it so I don't know which one is the best to get. A lot of people using the more unpleasant stuff cut it with oil to be more tolerable. I believe you can get to the universal link that scrolls on the top of the site and they carry oil.
I went to universals site and you can pick from Cottonseed,Grapeseed,Peanut, or Sesameseed. Like I mentioned I don't know which oil is best but you can get it in 50 or 100ml vials. They are also sterile.