Coco is safer than any peat moss mix because the pH is neutral and stable. It's also cheap and easy to deal with, and when you are done with it, you can toss it outside in the yard, unlike perlite, which has to be put in the rubbish or you can TOTALLY see it... my vegetable patch is loaded with perlite from past grows and I'm kind of regretting it... too obvious, ya know?
I would not use only perlite and vermiculite unless you are setting up your grow really as a hydro grow.

I am about to start messing around with a combination of coco, compost, and perlite. Keep y'alls posted on that one.