Sexpedition87

ok ive seen and rad some threads on lowering and one question i have that i havent seen answered is what the best way to lower the front that has the best ride.i heard drop lower control arm becuase you still use your factory spring.i just wanted some opinions and also will just lower control arms do it do i need uppers and do i have to replace the shock.also im debating between a 2" and 4" drop.its also going on a expedition.thanks for any help and opinions