our favourite fitteds are DnF, Weenotions NL, Luscious Little Somethings, Little Gumnut. Have to say though, I don't find any fitted nappies particularly slim fitting. If I need something slim fitting I go for an Itti or Easyfit
I actually find the opposite and find fitteds much slimmer than pockets under clothing!
Although M usually wears wool on her bottom half anyway so there's still genrally the one layer (no wrap needed) I love my T&Ts, WeeNotions Northern Lights, Dunk n Fluff and Holdens Landing fitteds. Little Gumnut aren't slim fitting as they are generously sized and are designed to be able to be used at night as well but I love ours overnight, especially the wool outer ones.