Speaking of "ladder stock," well, I'm finally happy with my arrangements.
IN the truck are three ladders, and ON the truck is one. Thes cover 90% of my needs. Back at the shop, I have several others.
I have a 2-ft double-sided step ladder. While sometimes used as a ladder, it's main use comes from the "Vee" formed by the sides whan opened. It's a work platform, great for holding pipe as I cut.
I used to use a 4-ft step ladder, until another contractor persuaded to the advantages of a 5-ft one. That extra step makes office work a breeze.
Then there is my real work-horse. Called a "7 ft combination ladder," it is either a 7-ft step ladder, or an extension ladder to 11 ft. It also has a bracket for leaning against poles.
Typical use: As step to open attic hatch, as extension to enter attic.
Atop the truck is a 20-ft extension ladder, to which I've added a pole bracket.
Back at the shop are:
-16 ft "4-way" ladder; service changes, open stairwells
-10 ft stepladder
-12 ft stepladder (regular cust store has 14' ceiling)
-24 ft extension
-20 ft cable/sign ladder (with hooks)