If u know how to work fiberglass or know a good body man i think that u splice 2 sets of together: use ext. cab steps for the front so that u have enough material to work with behind the door and some reg. cab step for the back doors... Then i would reinforce them will a little bit of metal something can nvr be to strong.

For the frame work i thought that i finally found a PA truck with a good set the first time i crawled over a pill of snow this winter it disintegrated so i got some 3/4" rigid conduit my Green Lee hand bent a back-back 90* i forget at what then i made another 90* bend on each stub and then again made 90* so it could bolt back in the factory locations im pretty bad at explaining stuff so if u dont understand me i made it look like the factory tube... then i capped the ends their galvanized so they'll out last the truck probably.