AMO bow length is measured from the tip notch following the curve of the limb on the belly side, then straight through the riser, and up the curve of the bottom limb to tip notch before the bow is strung.
There is no given AMO string length as far as I know. Depending on your limb design, and desired brace height , your string length can vary from 2”- 3” less. Most of my bows run 2.25” less and run 7” -7.25” brace heights.