Car Stereo Upgrade

[mega4ce]

So after doing much research on upgrading my stock system (2001.1 Path SE with Bose System and 6 disc changer) I am as confused as ever. My CD changer doesn't work and I want to have an iPod hook up.
I think I understand the basic stock setup. The DD head unit with CD changer, 2 amps in the doors controlling the front speakers, a rear amp (I don't know the location) controlling the rear speakers and I think I saw a Sub at the rear in the driver side quarter panel.
I have a Alpine HU being delivered today along with a Metra steering remote adapter, wiring harness and bracket. The HU is 18 W RMS X 4. I was planning on using stock speakers and amps, as mine seem to sound fine. My plan is to just wire the HU to the stock system using the remote turn on wire to power up the factory amp and limit the loudness via the HU to avoid the increased volume to the stock speakers. Does this seem like a good plan?
I have seen people recommend to bypass the factory amp, but then it seems to snowball. replace the stock speakers, run your own wiring, replace the factory amp with an aftermarket one, etc. I don't want to do an entire system, just get a working head unit. Also, I don't want to lose the stock tweeters. However, I'd rather do it right then do it twice. Any input would be appreciated.

[mega4ce]

P.s. sorry if this seems redundant. After looking at many post on different forums I figured I would just lay out my issues and plans and see what you all had to say.

[Towncivilian]

There is no subwoofer.

Get a line output converter and hook it up to your head unit and you will retain the Bose door speakers and tweeters.

[mega4ce]

Ok. It must be the amp that I saw. With the line output converter would I still run through the factory amp?

[Towncivilian]

Yes, leave the Bose setup intact. Just install the new head unit using a line output converter.

[mega4ce]

So after a quick look, I wire the line out converter to the wiring harness at the head unit and use the RCAs from the new deck in to the line out converter? So, HU RCA --> line out converter --> wiring harness --> amp/speakers?

[Towncivilian]

I did not use RCA, I just used the output wires of the HU to the input areas (sorry, I don't remember what they're called at the moment...) of the converter and the wiring harness side connects to the output side of the converter. If this doesn't make sense, I can post a picture later of the converter from my old HU.

[mega4ce]

Ahhh. That makes sense. Once I looked at a few types I saw a model similar to what you described. The earlier one that I mentioned and wires to RCA output. Not wire to wire, or RCA to RCA.

[mega4ce]

Thanks for the info