Wayne I am not a real body guy, but I did some lead work on my car body. I also bought the Eastwood kit because it had the tallow, files and paddles and I used a MAPP gas torch and it worked fine (just a little hotter than propane). I think I also bought a leading video to watch. If you go on Youtube there is really good video by Gene Winfield.
https://www.youtube.com/watch?v=87fuTnBS2bE
Having done this myself, I can tell you he has some really good tips that were not in the leading video I bought, and some mistakes I made could have been avoided by watching him. It is sort of a messy slow process and you may want to practice on a scrap panel for a few hours to gain confidence and even decide if this is for you. Because the area around the window is curved it will be more difficult to clean and you will probably have to use a die grinder to contour the lead since a file won't fit in there. It does grind and cut really easy and you can chamfer and round corners really well. Here is a photo from Sled Alley on one of Mark's cars that shows how they worked in the roof seam and it looks like they blended the corner a little also.
I can't remember is the roof seam finished on your car? For example if you want to lead right next to plastic filler it won't work very well. Hope that's some food for thought!