even if they only bolt to the body, that would be ok. my homemade 4X4X1/4 are very stout and i only bolted to body. i don't think they are going anywhere. if you get them and you want to modify a little, so be it. you can make your own for around $60 worth of steel. they can cut the length for you at the yard if you don't have a sawsall or a truck to haul a 10' stick. just paint it, jack it up to the frame/body, drill holes through it and the body, install bolts/nuts. don't need a welder.
only one problem though- they won't have that cool little "W" in the steel.