Is it a plenum ceiling? If so, you can't install any speakers into the ceiling that are not plenum rated and designed for that type of environment by electrical code. This includes the speaker wire itself which MUST be plenum rated.

If the ceiling space is not a plenum and can use anything, then the Monoprice speakers are MUCH higher quality than the Pyle stuff which is just garbage. Pure garbage.

If you need plenum speakers, there are inexpensive options out there, but you need to know for sure what it is you're dealing with. Then, I would get a small quality amplifier like this one which can sit under the ceiling near the projector like this one...https://www.ebay.com/itm/265941981015

That will give you proper amplification for any 8-ohm speakers in use. You can use a 3.5mm to 3.5mm stereo audio cable to connect the amp to the projector easily.https://www.amazon.com/Amazon-Basics-Speaker-Subwoofer-Gold-Plated/dp/B00NO73MUQ/ref=sr_1_6

If the space above the ceiling is a plenum, it will violate fire code, which can hamper insurance if it is ever needed, so it is legally required to use proper wiring and speakers in such a situation, and you should know what you are working with. In such a case, you will need a commercial speaker as well which can go up into the plenum. They tend to cost a fair bit more money (about $100 per speaker) to do this. Or you can mount speakers inside the room and just surface run cabling, or get plenum cabling to feed them. The amplifier cannot go into the ceiling if it is a plenum space.

If there are air returns in the ceiling which are not ducted, then the ceiling is part of the air handling space, and is a plenum that requires that added consideration. Something like these would be a fairly inexpensive option and they include plenum rated speaker wire which can be run to the amplifier I linked above...
https://www.amazon.com/Dayton-Audio-CSK658-Plenum-Speaker/dp/B002TVPVU2/ref=sr_1_6