IMO, the best thing to learn on, is the Igo-L.
Its cheap, so no worries there. Its also very simple, so while anyone can get going with it, once you DO get the hang of it, its a great rebuildable dripper(RDA).
The reason why I suggest this one, is because the air hole doesn't need to be modified out of the box. Its a little small for cloud chasing, for otherwise its fine.
And if you want a Genesis style, I suggest the RSST. For first time genesis builders, its great. And like the Igo-L, its a solid device on its own.
For the dripper, and since your on a VV device, get 32gauge kanthal. 32gauge is higher resistance than 30gauge, and for a VV device, ideal. Perhaps some 30 as well. Also gonna need silica. I like 3mm. 2mm is good too. Also might want to get some cotton.. either organic cotton balls, or sterile rolled cotton from CVS or the like.
For the Genesis, same wire, but get some SS mesh as well. I personally use only 400, but anything from 325 to 500 is used.
Since you're building on a Vv device, the lowest resistance you're going to want to build, is 1.3, and Id probably make it 1.5