Does anyone know where I can get life sife size Michael Myers from?
Buy a mannequin, coveralls, boots and mask. Put it all together. That’s how we do it. 
Where do I buy them? The mannequin
Ebay or Amazon
I bought one online a few years ago from a distributor in New York. I bought a couple from a guy near me as well called “The Mannequin Man”.
You can get the mannequinn cheap used, I got mine on kijiji the canadian version of craigslist. I think mine was $70 delivered