Be prepared, it probably won't fit no matter what...So far, every panel I've bought has been at best an approxamation of the original part. I've had a few that were so far off, it was like somebody had made it with a faded polaroid of the original as their only reference!

But they are still a hell of alot better than starting form scratch with a flat piece of sheet steel.
That said, don't be afraid to cut pieces to fit! This truck is teh first real auto body metal work I've done, the first few times I cut either my new parts or the truck herself, I was super nervous. Now its no big deal, cut, weld, grind, on to the next bit. I would also get a set of body hammers and dollys, I have the el cheapo set from Harbor Freight, and it has been invaluable. Takes a lot more time than I thought, but it has been a lot of fun.
Thats way more info than you wanted, sorry!