Hi Tran imam - I was just in Oakland last week-end for a stop at Tasty Vapors. They specialize in DIY Flavorings but the best values are what they call doublers 2&4 oz. You get a huge amount of juice that you then can add your own amount of nicotine. But you wanted to know about hardware. Tast Vapors has a very slim selection as they focus on juice. Go to vaporsearchusa. It will bring up a map that shows you what might be in your area. Even if they are only online you can make the order and then ask to pick it up. I remember something in Lafayette. Don't miss the Deals and Steals in the upper right corner. That will take you to a facebook group with great info and sale exchange. Don't end up like me with no back ups available. Grab yourself some fun toys while waiting for that must have hard to find special PV. if there's 1 thing I've learned you can't have too many batteries or Mods! Have fun!