You could save some money buying a mod with internal batteries like one of the mvps, coolfire IV or an istick. How much power you'll need will depend on your tank choice. The mvp pro goes up to 60W.
As for a tank, not sure if you want a rebuildable or factory coils? That new Aspire Triton looks very versatile based on Busardo's review. The Subtank mini seems very popular also.