Buckeye1982

So I'm adding my LOD tire carrier onto the bumper then of course my 20inch rim and 35 tire onto it. LOD bumper itself weighs a lot and then add tire weight. I'm prob obiv going to need spacers but not sure what size. Should I wait to put it all on then pay someone again just to add spacers cause I'm not good with that stuff. If so how you figure out the size? Obiv just be for the rear. And if not what size should I get or anyone do this and know what size to get? I have a sahara 4 door with 4 inch lift. Please need some help.