Can you clarify what you mean? Your statement is confusing to me but if I understand it better I can get to work on it.
Take a look at Imp's powered power armor mod for FO3 - one of the many things that mod does, is what he is talking about here.
(The "Recon Armor" was supposed to be what is worn underneath PA -- so the idea is that you actually CAN wear it underneath... not in any graphical sense, but in a way that adds to your protection or gives you some other benefit, while wearing PA with the underarmor... seriously, check out powered power armor though, that should help clear it up for you)