For Sherrelwood jobs we carry standard door sections and track in common widths, plus extra jamb trim and shim stock, because older framing rarely comes back square. If the opening turns out non-standard, that's a special order - the truck can't carry every size, and we won't pretend otherwise.
We stock both steel and insulated steel sections, plus torsion spring sets sized to the door weight, not a one-size guess. Openers go on the truck pre-selected for the visit based on what we discussed on the phone, not swapped out on-site, so we're not guessing at horsepower or drive type in someone's driveway.
One thing we don't carry: wood doors or custom architectural panels. If that's what a homeowner wants, we'll say so rather than sell a substitute and call it close enough.