there really are acres of info out there if u can be bothered finding it out mate. SEARCH again.
Just spend some time researching, its either now via the net, or walking around a wreckers for a few days seeing what will fit together. nothing in this world often comes free.
in 2 mins i was able to find a few relevant articles and sites, with multilple suggestions as to what can be used.. some may be on ke55 but they are fairly similar to your ke3x i believe..
You want a CLEAR explanation set down in front of you all laid out?
What do u want to get out of this? maybe u should be CLEARER on what result u are after:
how many horses are u planning to stop?
Track/circuit car? street car? mums car?
4 stud?/5 stud?
what diameter disc? vented/solid?
what caliper do u want? 1spot, 2spot, 4 spot?
how much do u care about unsprung weight ie heavy calipers?
what offset are your wheels?
can ur wheels inside-diameter accomodate a bigger disc/caliper?
etc...
HOW MUCH DO U WANT TO SPEND?