Ralliart calipers will fit on any Lancer model below us. All you need is the RA caliper, along with the caliper bracket, and the RA rotor. TRUST ME I know this to be 100% true. I don't know if the front hubs are ABSOLUTELY 100% IDENTICAL for all Lancers, sans the Evo. But I can tell you that the caliper mounting point location and depth is identical. I have a base Lancer spindle sitting in my basement right now that I used to test fit the 6 pot Brembo big brake kit I am selling. They are interchangeable. The only reason I haven't sold mine yet is I don't have enough posts to post things for sale on the "other" board where all the NA guys hang out
Here is a link where someone has done it (RA on a GTS)..
http://9glancers.com/index.php?topic=20784.0
And on topic, I don't think I need to express my opinion on the Ksport kit, as it is well known. But if I was someone considering it, I might ask myself who actually makes those calipers, what do I do if I need to rebuild them, where can I get replacement pads, where can I get replacement rotors, etc....