IMHO, if I had my time again I would opt for a low-mount over a high-mount simply due to the EPA emissions risk when the po-po pop the bonnet.
With a low-mount, you can keep it hidden and stealth looking if you play your cards right. With a high-mount, it doesn't matter what you paint black or how much heatshielding you use, there's no hiding the aftermarket turbo.
Try sort out the issues with the low-mount if you can, but if you really want a high-mount..... just buy my car instead. I've already sorted out all the headaches, just jump in and drive hahaha