Mr. Puffer has a small external plastic tube, might be a problem.
GG AFS holds a couple of ml of juice, might work for you (pricey)
Carlos' Juice Box is (I believe) bottom fed, so the whole thing is internal. (pricey)
Craig @ ecigmods.com is releasing a new juicebox type that has internal feed and is $70-$80. (Taking preorders now)
Not advocating for or against any particular model. The higher priced models tend to be well constructed and durable. The GG might be popular at work, considering it is made from machined high grade aluminum. His auto feed system V2 was just released, with a bunch of improvements in useability and capacity. I is also completely sealed, and can be washed externally while full if you cover the mouth hole.
Good luck.