thanks for the info. So if i wanted to use an rsx billet shifter and cables I would have to change the shift mechanism in my k20z trans?yes you can mate any 5 or 6 speed manual trans to any K20A/Z or K24A series engine.
The shift mechanism on the transmission will dictate what shifter cables and shift box you need to use.
For the clutch and flywheel its best to switch up to a RSX Type-S or K20Z3 parts - basically 6speed clutch kit + flywheel parts. The K24A + base model K20's that come with a 5-speed transmission tend to have a different flywheel + clutch (pressure plate) specifically with the clocking of the pressure plate alignment pins on the flywheel, to which the 5speed pressure plate conforms to. Say in the event you want to run a lightened flywheel, manufacturers only really make lightened flywheels for the 6speed transmissions, so you wouldn't be able to mix 5 and 6-speed clutch+flywheel parts because of the difference in pressure plate pin clocking.
Also depending on what ecu (either 5speed or 6speed) you use for Kpro, you will not have reverse lockout functioning when using a 6speed ecu with a 5spd transmission or vice versa. You won't have to worry about this much though with a 5speed trans + 6spd ecu, its more of an important thing for 6speed transmission use.