Trouble picking out headers

don't think you'll need to be worried about either one of those...

shorties should clear the PS ram and any tranny clearance issues can be resolved in the exhaust pipes.

as far as the z-bar...not quite sure about clearance there, I've never dealt with one. just give summit a call! They'll let you know
 
My JBA's cleared the Z bar after I took a torch to them and clearanced them. Same for the steering box.

I think you can get a power steering ram drop bracket, which opens up your header selection to long tubes..........