proper sub/amp to complement system?

Recently I have decided to upgrade the stereo system in my 2002 jetta 1.8t.  After a lot of listening to different products, reading and opinions I decided to remove the entire system and start from scratch.   I used a set of cdt audio hd-62s for the front stage, and a set of cdt cl-61s for the rear fill.  These are all powered by an audison srx-4 amplifier.  The head unit is a jvc shx750 which is nothing special but it get the job done.  I am now faced with the task of choosing a sub and sub amp that will match my current setup well.  Keep in mind that I am by no means the type of person that wants to rattle my rear-view mirror off, but I do enjoy listening to rap music on occasion as well many other types of music.  I would really like a very "musical" sub.  My recent considerations are alumapro, image dynamics, jL (although I would like to try something different), and boston.    I have no clue what to do for an amp.   Please point me in the right direction and give me some ideas.   Any input will be greatly appreciated.   Thanks. 

Start by listening, you are on the right track. The above mentioned brands are all good choices, in my opnion. I also feel that a single sub setup, with the proper enclosure and power would be a perfect compliment to your system. A mono amp or a two channel would be ideal here. Determine how much you want to invest in both. It is usually best to purchase an amp first, but you could plan for both simultaneously.