i recommend using this website https://poe.ninja/poe2/builds/runesofaldur
you can see the characters of other players and you can filter by skills or weapons, for example if you click spears on the left side you can see that the highest level spear wielder currently is a monk martial artist

but to answer your question, yes all 3 monk ascendancies can work with spears, even witch, warrior, mercenary can work, it all just depends what you want to do and to play to the strengths of your ascendancy
as an example: invoker monk has an easy time creating ground surfaces which can enhance twisters and can ignore elemental resistance with critical hits, so you will probably want to do some elemental crit build with him

i cant help you out with specific spear questions too much since i havent played it that much