There's a few companies that make kits to where you swap the alternator to the driver side,and the ps is below that. This is without AC of course.The alternator is close to the turbo for sure, but with the turbo blanket it's not an issue. I'm not sure what you mean about drop the PS down? It fits fine with the forward facing headers.
The on3 install was not bad at all. Actually, pretty straight forward. The hardest part was tapping the oil pan for the return line.