Drop kits for my 71 c-10

[Alaskan71]

I need help, I'm new at this and I am in the slow process of restoring my 71 chevy. I want to put a drop kit on it and although i like the looks of the 4/6 better, it is too low for Alaska roads and I have settled with the idea of the 3/5 drop kit instead.

Does anyone have any suggestions as to the best kits to get or the best way to go about this? my truck is an older 71 with coils all the way around and this may be a rookie question, but what is the difference between drop coils in the front and drop spindles?

Thank you for any information you might have