The police/fleet vehicles normally used the heavier (larger) versions of parts.
For example:
1) Tie-Rods
- 9/16" for standard
- 11/16" for police/fleet (TRW: ES355L & ES352R rod ends, ES440S sleeve)
You can still get the hard parts.
2) Sway Bars
- 7/8" for standard
- 1-1/8" for police/fleet
The soft stuff (bushings) are still available (aftermarket, or occasionally eBag OEM stuff). The hard part is a mix of both stripped down factory cars as well as aftermarket (look at FirmFeel).
The other stuff ( Pitman arm, idler arm, etc.) like
@Mikes5thAve said is still available but you may need to fish around for the right part that would have been the preferred police/fleet part (thinking something like the idler arm, on the topic of which we had a thread not too long ago with specific part #'s listed, so let the SEARCH lead you to it)