'93 Ford Ranger Stock head unit to LOC/amp questions

So earlier this year I got a 93 Ford Ranger and I want to keep the stock head unit, but the sound system needs some TLC. I picked up some Kicker KS 6x8 for the front, and Hertz DCX 130.3 5 1/4" for the lower cab corners in the rear. I definitely want to get the most out of these speakers and plan on installing a sub down the line as well and for this I'm assuming I'm going to need a 5 channel amp.

So I picked up a D4S HiLOC5i for my line output converter, but I'm a little confused about the wiring for the LOC. Would it be best to tap into the stock wiring harness and use those L/R Front and Rear cables to the input portion of the LOC? I'm assuming I don't go directly from the speaker to LOC or am I mistaken?

And then obviously from the LOC I attach the RCA cables to the AMP, right? Sorry for my ignorance, just trying to get everything understood and sorted before I tackle this project! Thanks in advanced.