I'd recommend the Vivi Nova 3.5ml tank. That has a replaceable coil that you can easily switch out. It comes with three of them at 1.8, 2.4, and 2.8 ohm. I don't think it's either a clearomizer or a cartomizer tank, but I believe it works like a clearomizer. Don't quote me on that, please. I'm relatively new so I don't have a firm grasp on the terminology. Or, if you want to go with cartomizer
tanks, for starting out I'd recommend the smoktech's DCT
tanks, and get some pre-punched (or I guess you can punch them yourself if you want) single-coil cartomizers to start out. Most DCT tanks come with cartomizers, so I guess you don't really need to get more cartomizers until you know you like the system.