Upgrade stereo in JK
 

I have a Wrangler X. I have upgraded and purchased My gig "RER". I also purchased a Sub woofer & Amp "OEM" that mounts in vehicle. I will not be able to use the amp because the pigtail does not have a mating part in the wiring harness. I think I can use the sub though, what I need is verfication that a single chanel amp will work in this application. So basically I am just adding a Sub to the 6 stock speakers. Also what size Amp do you need for roughly 10 inch speaker?

Yes, a mono (single) channel amp will work. Get one either with speaker level inputs or get a speaker level to preamp output converter adn drive the amp with the normal RCA inputs.

As for size, look at the back of the speaker. It will have a maximum watt rating. Get an amp that size or maybe a little bigger. 100W speaker would be ok with a 125W amp. That same 100W speaker with a 1000 watt amp will only last for a few seconds.