Eric,
Rack & pinion steering is definitely not going to be part of this build, I'm already tapped-out with all of the unplanned upgrades I've made to the brakes and suspension. I have a nice Lee 12.7:1 power steering box in the car that's 20 years old and still going strong.
I was already having issues with the deep backspacing on the 18X9" front wheels, the rim was hitting the rearmost tube on the Hotchkis upper control arms near full steering lock. I bought the SPC adjustable uppers to gain some clearance there (straight adjuster vs outward curved tube) and it just sort of snowballed into a complete front end upgrade.
The limited turning radius won't be any big deal. It was already reduced with the B-body spindles with their longer steering arms (I hardly noticed the reduced radius), the new ATS spindles will give me some turning radius back so it's probably a wash.
Having the tierod end (grease zerk removed, a plug in there instead) touch the pan once in a while won't hurt it. If the new SPC upper arms don't have enough clearance to prevent the rim from rubbing, the limited travel of the centerlink will.
Bart