OK, Here's what I did.. and I'm no expert, but I think it worked out great.
New stuff I put in -
Alpine 9853 head unit
Alpine 345 4channel amp
Boston acoustic SL60 component speakers in the front kick panels and tweeter in the doors (I removed the old mids and highs)
All new speaker wiring
What I left in-
The two tiny rear speakers
The stock sub box with HK drivers
I am driving the two kickpanel/door speaker sets from two front channels of the amp which is in turn driven from the front preamp outs of the headunit. The subwoofer preouts from the headunit go to the other two channels of the amp that in turn drives the two little drivers in the stock subwoofer box. I drive the two tiny speakers behind the seats with the two rear amplified outputs directly from the headunit. This is why I bought a headunit with a built-in amp.
This sounds pretty simple, but in fact it was a huge PITA. The hard parts were... pretty much all of it. Took me a couple weeks of intermittant progress.
I will post more details later, but some challenges were:
Getting the wiring for the new door tweeters through the small rubber snorkel from the body to the doors.
Mounting the three-holed BA speakers on the irregular surface behind the kickpanels. Figuring out how to get the plastic structure behind the seats apart so as to run wires under/thru it. Fishing the wires thru the rubber grommet between the trunk and the interier with the top up in the hot sun.. (Had to work outside because the doors needed to be wide open and my garage is not that big).
Anyway the thing sounds awsome. I am going to go deaf from actually being able to hear the full range while crusing at 80 beside 18-wheelers on I-495 with the top down.
The BAs with the separate tweaters and crossovers are increadable. Be sure to set the jumpered tweater attenuation (-2db) so that your ears don't bleed ;-) The little subwoofer actually does pretty good if you drive both drivers with 75 watts (reverse the polarity of the rear driver). Remember to put the snorkel back in as the little drivers need damping to keep them from destroying themselves The snorkel seems to restrict them just enough to sound deep and stop slapping around. The little speakers behind the seats do a good job of filling in mid highs and I can in fact hear them destinctly now.
The head unit takes a while to figure out, but once you get the hang of setting up the equalizer and time delay you can tone down the highs a bit and boost the bass to compensate for the open car syndrome.
I am pleased...