Prius Sound Upgrades

have just bought a 2008 prius (and love it) and i am looking to upgrade the sound system.

i really don't know where to start so i thought i would ask you a couple of questions, maybe someone can help.

the music i listen to is really wide variety, but i am especially concerned about listening to electronica and house, which has very strong crisp bass sounds.

i would like to upgrade the sound system and here are some ideas and thoughts ... any feedback at all would be appreciated

i am considering the following two products

http://www.priusownersgroup.com/?page_id=1122

This kenwood seems to do the trick and fits in the small compartmetn of the prius, but it may not have enough bass (bases on a handful of reviews i have read)

the other option is:

http://www.lacar.com/modules.php?name=News&file=article&sid=392

this seems to be much stronge.

here are a couple of concerns:

i don't want to mess with the electronic system of a prius at all! the kenwood has its own amplifier which seems to be much easier and less risky. my fear of this is mainly because i am not aware how the electronic system can be damaged

i will not install the system myself and will have a professional do it

are prius's typically dificult cars to alter the sound system?

what risks are there?

can you recommend any specific products which would be good for increasing bass on a prius?

any information would be much appreciated

thank you