please please help me (98 jetta audio)

Ok, i am new to this forum and I hope somone will be able to help me out. Heres my dilemma. I just purchased a 1998 Jetta GL, and i love it. I want to modify the sound system, I plan on adding 2 sets of 6.5 Phoenix Gold Octane R component speakers, and some amps to power em. Now, i don't want to add an aftermarket head unit, i like the stock look and the cd changer in the trunk. So i plan to use a "AudioLink PowerLink II
Line Output Converter" to convert the speaker signal to RCA input in the amps.

This is where the problem lies, i need to get a full signal to input in the amp. Where do i wire the converter to, i realize the back speakers are components and if i choose to wire them, i need to get it pre crossover, where are the crossovers in the Jetta? OR i can wire them to the front speakers, but as i Have 2 in the dash and 2 in the door, does anyone know if the door speakers are coaxels or they are components and the tweeters are in the dash? or are those seperate coaxels in the dash?

any ideas would be GREATLY appreciated
thanks a million
ben