just got my 4" Readylift installed and it looks perfect. got a couple more small mods in the works but will be posting my first pictures on here soon.
i initially bought 295/65/20 nitto trail grapplers (35.47" x 12.13") but they just wouldn't fit. ended up switching to ridge grapplers instead which are about 3/8" narrower in that size. i'm running the factory 20" wheels so it's been a bit more problematic than an aftermarket wheel would be.
FYI for those out there considering using the factory 20's with this lift kit and 295/65/20's you WILL require a 1/4" spacer in the front only. the tires will touch the UCA when the truck is in the air but once it's on the ground you should have ~3/16" to 1/4" gap. very slight rub on the felt liner but only at full lock.
you can run wider tires with this lift + factory wheels, but it'll require bigger spacers and trimming your lugs or lug nuts. my advise is get some aftermarket wheels if your budget will allow it.