man united have shown great promise for the future in recent matches .
louis van gaal has a decent squad at old trafford but must add to it .
gareth bale , memphis depay , mats hummels and nathaniel clyne on list .
van gaal is a serial winner and can get united challenging for honours .
dutchman will want to leave united with record that compares to sir alex .
read : liverpool launch bid to rival man utd for psv winger depay .