Yes, there are many types of cables, but perhaps I take it for granted what each type will do. In The Oztules book, A4 size 76pp 176 colour photos, I do explain about the different cables.
And the primary in my opinion should be the stiff, a few thick copper twisted strands, hook up wire, its also cheaper, but don't bash it to hard or the thin insulation just splits.
Although 'oztules' mentions somewhere in his 'conversations' that the centre holding bolt and plate will keep the primary coils in place.
I go straight to Tri rated, multi stranded, welder, battery flex, very flexible cable, after the primary is done its last/first turn.