well for starters it really depends on what you want, does size play a big part in what you want? I would say start with an ego twist and a vision vivi nova. Then you go to places like copper creek e juice or AVE e juice or many other suppliers to get your choice in flavored liquid. If you want something thats about the size of a cigarette that have already filled cartridges then I would say NJOY but i would stay away from that stuff anf go with an ego. But like I said its all about what you want for size. Also you could go with boge low resistance dripping atties if you dont mind filling up almost everytime you use it, bc they have to be filled up so often they are very compact and the atomizer becomes the size of your thumb. Batteries are the same deal the longer the life of the battery the bigger it becomes. Try to figure out what you want in size and how often you want to fill it up with juice and we will be able to help you out a little more