You can't get a 'kit' to bolt on, to tuck 20's.
Sorry kid, it's not going to happen.
I have a 5" drop and I'm barely tucking rubber on my 18's. And anything more than 2.75", and you should C-notch the rear.
And as for the Explorer Body Kit, there are already a couple out there, and nobody has even bought THEM....why waste the time, effort, and money on another one that nobody will buy?
Ryan