Saw some folks on here recommend Infinity Kappa 652-5i's.
Crutchfiled says they grade the best possible fit with no adaptations.

BUT, I bought them through E-bay:

http://cgi.ebay.com/ws/eBayISAPI.dl...ADME:B:EOT:US:3

Any wiring harnesses or the such that I am going to have to worry about?

I was trying to find Rockford Fosgate Subs for the back. But, could not find the 4406/3406 on E-bay. With the stock system, I never had problems with bass so I am hoping these will work on the doors and the back (rear seat)... crutchfield said they would work either place:

 

yeah, we had a huge post going on this for the Monsoon system a few months ago.

the monsoon is 2 ohm, so you won't get as much power/bass/spl out of the replacement speakers.

I would get the SoundStream 2 ohm speakers if I had to do it again.

i put in Boston acoustic 2 ways.

the stock monsoon has 4 wires (b-amp) to each door speaker, FWIW. i ran a extra tweeter on the A pillar.

i rode in it last nite (wife's car) and now with the fader flat and stock speakers in rear, the sound seems to come from the rear.