Just read thru the thread. It looks like a great build. I actually drove up to San Antonio to cut the trunk divider out another guys car. that is what i welding into mine. In your case, patching isn't going to be so bad. you can probably use 20-22 gauge sheetmetal. you can find it at your local Lowe's. I can't tell you how much metal i bought from there. Take your time and plan, plan plan. I still change my mind constantly. LOL.