Here, your link gives you a download for the specs, and the manual. So get that. I think it tells you the answer to all your questions.
http://www.kicker.com/app/manuals/amplifiers/cx/2012_CX_Mono_Amps_RevI.pdf
You do need to carefully match the speakers to the amp for the ohms impedance match. I am not sure what you want to hook up? One big woofer? That would be a 2 ohm 600 watt job.
This would be new stuff to me, never seen 2 ohm speakers. 4 and 8 is all I have ever use. So get this right or boom goes the amp.
According to this, you need 8 guage wire to power the amp from your power distribution panel to the amp. No need to worry about noise on this wire just use copper auto electrical 8 guage wire
but don't runs this stuff through sharp edged metal holes. Use rubber grommets like someone else told you. If you fuse the power source at the panel where you pick up the 12v power, you will be cool and not burn car up.
You really do not need to worry about the watts (600 or 300) cable you use to run from the amp to the speaker(s). Most coax will do, RG8 would do fine. It is the size of power wires to the amp that you need to get close to right, 8 guage. I think 10 would too, hard for me to think your car is long enough to need 8, but they call for 8.
Drill your hole, you can do it!!! Just check both sides, dirill in, drill out.