How powerful are the Toa Nuva, Makuta, and Mata Nui? For example, could the Toa Nuva with all of them having all six Kanohi Nuva and their elemental powers take on the JLA?
First, We can look at strength: Onua Nuva has shown that he can lift many boulders of large size. Also, Phohatu, even without a Kanohi, in v1.0, tore a slab of solid rock straight from the ground.

Speed: The Toa Nuva are able to, while using kanohi Nuva, to move so fast that they are just a blure. Also, the Toa Nuva, while using the Kakama Nuva, can pass through solid objects.

Protection: The Hau Nuva can protect from the "most powerful attacks". The Toa just can't be ambushed.

Kaukau Nuva will let the Toa Nuva breathe under water for an unlimited time.

Flight: The Miru Nuva will let the Toa Nuva "soar into the air and reach amazing heights. Also, if the Toa Nuva combine the Miru nuva and the Kakama Nuva they can fly at super speeds.

The Akaku Nuva will let the Toa Nuva see any object hiden by physical means or by an illusion.

I've given you the facts, who do you think would win?

I have kinda been wondering that too. I think that for sure the toa would win, but what if an enemy distracts them or catches them off guard? Besides, we don't even know exacly howw powerful makuta or the other enemies are, so it is a tough question.
K-9

Uh dude why did you post the same topic 13 times?
Any way yeah i was wondering this too.

with protection it doesn't work with ambush

I think the Toa don't gain power from the Kanohi (Except mask of Strength) they gain intelligence from them and can outsmart their opponents...