Why do my brakes squeak?

There's a slim chance that your squeaking is not related to your your wheels/tires at all. Depending on how mechanically inclined you are, either pop off a wheel and look for the problem in the brakes, or get it a looked at by a pro.

If the noise is coming from your new setup, I'd still follow the same steps as listed above, just keep an eye out for brake/suspension parts rubbing on your wheels, or anything that looks a little too close for comfort..

Also, are your wheels and tires different sizes than the stock ones? If so, you could have thrown off your alignment. That's a job for a pro also, unless you know how to do it the old fashioned way. Good luck.

Do you think you should look to find what is rubbing before you wear through the new wheels or brake calipers? Do you think?

probably either brake dust or the backing plate behind the rotors got bent !