It might not be worth it. I have a S-type sport with the same suspension as the S-type "R". I wanted to convert to the "R" Brembos. So I went out and pieced together the calipers, rotors, front spindles and hubs. I also got the entire rear end off the "R" (all very hard to find and very expensive in good condition). Plus unless you guys have the same push button parking break I don't think it will work as the "R" Brembos have a separate E-brake caliper which means you would have to get the "R" cable and for good measure I suggest the "R" actuator.
If I were you and they fit your car. I would run this Coilover. $1400 is quite affordable if you think about it. The only thing that makes the S-type any better would be the CATS system which I believe your cars don't have. So in short it's pointless.
Well someone did non-brembo R brakes and they are still a nice upgrade. As for the Push button electronic brake, we do have that on the 2003 - 2006 LS.
http://www.lincolnvscadillac.com/showthread.php?t=83858