Just a few more.

For port sizes
http://www.linearteam.dk/default.asp...ventcalculator

This one has just about everything you would want to know.
http://www.bcae1.com/

For wiring subs
http://www.crutchfieldadvisor.com/S-...pedance=DVC4x2

This one is cool for testing subs.
http://www.soundcheckproaudio.com/bassdisk.htm

Box sizes
http://www.rockfordfosgate.com/webwi...alculator.html

 

Seems like this has been pretty thoroughly covered, but I went with the Pioneer DEH-P7600MP head unit ($230 new on e-bay) because it has the 4V preamp outputs. I'm driving the kappas with the Pioneer for now but will add an amp later. Yes, they do require an amp to get the most out of them. Anybody suggest a good amp? I haven't shopped in years.

In back I've got a 6" bazooka tube RS powered by and 80 watt bridged Carver amp. Does a pretty decent job.

 

It would be nice if you could get your hands on a Carver 4 channel amp to match if they make such a thing.

Kicker, JBL, Soundstream, MTX
Any one of those and more would work with the kappas. Just check out E-bay.
Just make sure that all 4 channels (or both sets) have a High pass filter on which ever amp you get.

 

I went with Pioneer TS-A6880 all the way around. Sounds awesome. Now I just need the Alpine CDA-9815 that I want. Oh, and a subbox.net box with 2-10"

 

Cool, nothing like enjoying what you install.
Check out the RE subs. They are hand made in your town. Might get a price break if you just pick them up. At lease give them a review since they are so close.
Congrats!

 

God, I love my AUDIOPHILE!!!

 

the Audiophile aint THAT great dude i dont know if you've tried out aftermarket speakers or not but it might change your perspective on spending $300 on the Audiophile.