love the examples you posted, especially FKA twigs :U: :U: and the Rosie Lowe song.
the production by Arca on FKA Twigs' latest ep is insanely good
i want to produce stuff along the lines of this, im not anywhere near good enough though... it's really hard. it's so polished, and does seem to be made ...

i'd say your best bet would be a shure sm58- they're the industry standard and work well live too, if you ever need it for that. you might not even have to upgrade it