You will want to use 2x3 inch box tubing for most of your rear frame section except for the two short legs where you will tie into the existing frame. there you will proberly want to use 4x4 box tubing. You should be able to purchase this for about $100.00 or so.then what are you doing for rear suspension, trying to adapt what you have, or going to ladder bars,4-link or what? You can price them out in Summit or Jegs book. How about Shocks or coilovers