More content. Why? This is what i would do:
Get myself a content goal (let's say 100k words) then get some backlinks after i reach it (Multi tiered/Guest Posts/Niche edits), then set another content goal and so on.
Why i would do this? By the time i start with my second content goal, those 100k words start ranking and bring traffic.
Remember you can get your content ranked if you provide high quality links, but first you need to cover some topics of your niche.
What if you focus on backlinks, you get those 40k words ranked, ok, can those articles bring you enough cash to cover your expenses? (because guest posts and niche edits ain't cheap you know).
Cheers