Generally a long double like a double 16, is sstiffer and thus nicer to use than a shorter triple like a triple 12, but triple is easier to store and transport. A builders ladder will be stiffer and nicer, but heavier probably. Full alu is generally a lot lighter than wooden sided, but wooden may be stiffer (going on personnel experience but that’s of some old, albeit good, ladders).
A friend to help erect and stand on the bottom rung of the ladder is very very good. A bag of sand or ballast over the bottom helps if you don’t have a mate. I Will never forget endless very boring hours stood on a ladder as a little kid, while dad did various jobs up at the top. Very boring, but a cherished memory now he’s gone. Weird.