Best 4channel line out converter?

I'm brainstorming about what i am going to do with the sytem in the 03 Chevy Trailblazer that I am plannig on getting.
For a hassle free integration into the Onstar and steering wheel controls,and a stock look so as not to tempt prying eyes who might care to acquire my new gear,I am strongly considering keeping the factory head unit.
Others here have mentioned that a line out converter going back to my amps is the way to go.

I'm actually wondering what the best converter to use is? Will any specific one yield any more clarity than the others. I know a 3 dollar radio shack one will not cut it,but what about the Vendetta ones,etc?

I'm thinking of going from the converter into a line driver before my two JL amps(500/1 and 300/4)? Good idea or bad? Thanks for the help.

The vendetta ones are pretty good, as are the ones from david navone.  Soundgate makes some really nice LOCs too.

Why were you thinking of using the line driver?  To raise the voltage of the preamp signal going into the amps?  I dunno if that's going to be necessary really, but it certainly won't hurt the JL audio amps either as they can take a fairly high input voltage on their preamp inputs.

If you do end up using a line driver, just make sure you switch the "input voltage" switch to "high" for both amps;  also, according to JL they can handle up to 8V RMS input so don't set the line driver to output any more than that to each amp.

For most brands, a "Type 1" LOC would be any standard line output converter; a "Type 2" LOC would usually be called a "factory amplifier interface" or "factory premium system interface".

Wow,this gave me a lot of good info. Thank you!

I was originally thinking I would need/want a line driver to get a good S/N Ratio and stronger signal. Anyone think it would be a waste to get one?

Also,what type LOC would be suggested when adding to the OEM stereo? At this point I am not sure if the truck will have the Bose option or not. i am also not sure if the non Bose system uses an outboard amp or not. Can anyone shed some light on this for me?
Thanks again for the help!

Most likely the non bose system does NOT use an external amplifier.  With that in mind, it is very important to know which stereo system is in the vehicle (bose or non-bose).  With a non bose system you could only use a type 1 converter (high-level to low-level).

With a bose system, either type of converter can be used, but both types would require tapping in to completely different wires in the vehicle (and possibly completely different locations in the vehicle).

One thing I forgot to ask earlier was, what are the amps for?  I'm assuming the 500/1 is for subs, but what about the 300/4?  Are you installing aftermarket speakers and planning on powering them with the aftermarket jl amp?  I sure hope so because the bose speakers will only work with the bose amps, and likewise the bose amps will only power the bose speakers.