Aloicious - the tool your referring to is called a pinion depth tool, extremely expensive, and from what i hear makes setup a fawking dream, but of course its not needed
yeah, thats the one, could not for the life of me remember exactally what it was called.
OP, if you do a good job inspecting the gear contact pattern, you don't need the depth tool.
as far as the TQ wrench goes, you're right, though you can also use a good quality pneumatic wrench (one that can do at least around 500 ft/lbs, I wouldn't trust a harbor freight gun), just don't go crazy with it, you can't just back the nut off if you overtighten it with the crush coller on there. just do short bursts with the gun and check the pre-load between each burst.