Hey, ghaffar. Add my welcome also. FWIW I already deleted your duplicate posts.
What you are trying to do is a bit like making a silk purse out of a silk handkerchief: they are both made from the same stuff but there's just not enough to work with.
Or at the least it is going to cost you a bundle. I seem to recall reading somewhere that even the Brabus springs only drop it an inch and that it is much pricier than the 2wd models.
And while it is possible to run a staggered setup on the 4matic, it is very important to work with a trusted vendor to ensure a proper match...lest expensive troubles ensue.
In the end it is probably cheaper to sell the 4matic and buy a 2wd to mod as you like...and a beater Subaru to drive when it snows.
Take care and enjoy the ride,
Greg