mount it where you can that is out of the way and not near heat. some guys put them inside the car. if you dont have the battery up front, the old battery home can be a good place.
wires and coil are sorta ancillary - no harder to do when doing the box than not. do the wires one at a time in worried about messing the Firing order up. coil is a coil.
good luck.
I am using the MSD Digital 6, but where you install it has the same advantage/disadvantages. I made a non conductive platform, and mounted it where the glove box was. Allows room for other additions, and easy access.
I mounted my MSD6A in the right front fender right under the stock airbox area. Well hidden, kept the engine compartment uncluttered, & plenty of room for it there. My mistake? Mounting it upside down! I didn't read the large installation manual quite well enough & "the box" filled up with water that couldn't get out..... Live & learn
I mounted the replacement MSD6AL under the passenger seat & inside of the car.... I ran the wiring down the firewall, through the tranny tunnel, up through the shifter sealing boot, under the console, & under the carpet to the pass. side. So far...so good!
One of my freinds had a MSD 6AL mounted in his car right on the tranny tunnel. He told me that the box makes a ticking noise and heats up. Anyone done this or ever hear ticking from thier MSD box?