hey mark,
you're shopping list is correct mate.
I didnt do the fibreglass, i just did the body filler and it worked fine. To give it a backing i just used some cardboard behind the void.
Buy a can of spray putty to help fill the little pits. But try not to rely on this method.
It takes patience to get it right. I bogged mine, rubbed back with some 400. then re bogged, re sand, and re bogged. Takes a while, but you get a really nice smooth finish.
in terms of mixing body filler (and the glass if you use it) is just as simple as following whats on their packet. Dont add too much hardner to the filler if you're not good with working it quickly, or it will go off too soon and you'll be stuck with filler you cant use.
Also, allow a weekend to complete it. It took me saturday and sunday, but i was doing a few others things at the same time which increased the time.
I would say preparing it, it doesnt matter on weather, actually great for a rainy day. however, for painting, i always like low humidity, around 20degree outside temps, and a bit of breeze.
i have a mini oven set up in my garage to bake the paint. Consists of a massive flood light with halogen globe, and some old pc fans for air flow
hope this helps, and look forward to seeing it on the next cruise