Think I've finally found one

So, I know I’ve said I wasn’t going to do an aftermarket amp for the main speakers, but… I think I could make this work.

Again, this is with looking at:
New head unit:




My thought is to wire the sub in parallel so the final impedance (should) be 4 ohm, meaning at the rated output of the amp, the sub will be getting 350W RMS. Sub is still being planned to be installed behind the driver seat of a '02 Ford Ranger XLT, and the amp I’m considering installing under the driver seat. With me being the only driver, I don’t expect that seat to move, and at most, I may have one passenger in the back seat behind the passenger seat. I’m hoping this will mean less having to worry about things around the hardware moving, messing with cables and such.
I’m thinking about something akin to this for the instilation kit:

Though I am aware, I’m thinking I might be better off following the users manual for the amp and going with a 100A fuse.

If any of my logic isn’t making sense, or if there are any changes that should be made, beyond getting rid of the rear speakers, feel free to let me know.