Rusty roof replacement question. Questions, actually :)

[Tim_A]

Dear guys!
After several years of watching the orange 69 shorted stepside and a separate rolling chassis sitting in my garage, I decided to actually start restoring the truck and transferring it to the new chassis.
I seem to be pretty clear on all the restoration aspects except the roof. Below are the pics of the extent of the damage. I have no idea where to start. I have seen new outer skins in LMC, but the rust problem seems to be concentrated along the drip rails. Hence the questions:
1. As far as I understand the easiest way to solve my problem is replacing the whole roof with a donor one. Question is, where to find a donor roof? And is it realistic to expect to find one or am I going to get the same thing I already have? I will try to place a WTB post in classifieds, but maybe you know a place that can have one, or maybe someone has a roof he can spare (dreams, dreams).
2. If I do not find the roof. What parts do I have to get to replace it (outer skin, inner skin, front inner insert, left and right drip rails). What about the front drip rail above the windshield? I have not seen it in any catalogue.
3. If I buy all those parts, can someone point me in the direction of a detailed restoration report, explaining step-by-step roof restoration? I will definitely search this forum, but maybe you have seen something really good.
I will try to post updates on the truck transformation as I go. Thanks in advance for any advise!
Tim