yeah the reason for a high mount is more cooling and also there is more room available to work with one big single. it will be easier to manage.
Yet to be decided about the wiring loom, i will try and go for the GTST loom, (even tho mine has been cut 50 times and put back together) and go for the single AFM, but have to source out the PFC. or go with the GTR ProFC and get 2x Z32 AFM's.
I will be HPC the manifold as well for the extra cooling to make sure that it all runs well, unlike yourself i dont have the vented bonnet more money later on for that.