oh lord. please tell me you aren't going t do that to a raptor....
and get rid of the level kit, and go to mid perch. you mentioned you will offroad it, so do yourself a favor and get rid of it. and dont get 20's if you are going to offroad, terrible idea, especially since you mentioned you dont want to effect the ride. stick with 17's and dont go 12" wide. you will need a stupid wide tire for that, not to mention it would look so bad, and would not work as mentioned due to rubbing