I've got the HK system as well, not to sure what the components are in exact size, but that info should be around on the web. The system is running splits in the front and rear, and two free air subs in the back. Look around in the forum, or at DTMpower.
I'm happy with the splits, but not with the free air subs. People have replaced them with free air Kickers, but I'm not going this way. I've dynamatted the whole parcel shelf after taking the HK sub system off (it rattles like ****, and is not as punchy and powerful as I would like) and installed a Kicker solobaric sub. Much better. I also have a PPI art series A600.2, a digital crossover and all sorts of other sh*t in the system.