I'll take a swing at this
For the drag link, inner and outer tie rods, there should be no difference between manual and power. There was a "heavy duty" drag link available (based on David's info) but the basic parts should be fine.
There are three different length outer steering arms with manual cars typically using the longer arms to help with steering ratio. BUT that doesn't mean you can't use the arms you have. Best bet is to measure yours and compare to the info on David's page: http://www.pozziracing.com/camaro_st...part%20numbers
Power Steering Pitman arm is different than manual box -- you'll definitely need a new one. BUT there are two different lengths -- a "long" one for fast ratio and a "short" one for normal ratio. The arm that's "right" for you will depend on your outer steering arms. If you have the "long" steering arms, you'll want the "long" pitman arm as well. If you have the shorter steering arms, I'd recommend the short/normal pitman arm....
There seems to be only one idler arm available these days, so not really any options there.
Basically, the steering box ratio, pitman arm length, and steering arm length all play together to determine the overall steering ratio. Assuming you have the 12:1 steering box (?) the short pitman and short/power steering arms work well. Alternatively, if you already have the long steering arms, the long pitman arm and long/manual steering arms also work well (it's darn close to the same overall ratio).
I don't think I helped with the confusion....