I am a native English speaker (Hell, I'm actually English) and I can easily write relatively technical reviews, but in the spirit of full disclosure, Id probably end up involving poo at some point, so I may not be who you need. I could of course do it, and then you would have to remove the poo... But...
Thing is, the easiest thing would be for you to write the reviews yourself, and have people copy paste word for word. That way you would have a wide variety of different people, from all over the world, extolling the virtues of your product, in exactly the way you want it to appear, as if all different people, all over the world, all love your product
