HK speakers are paper cones and tweeters are plastic, strike 1. HK amp isn't very powerful and you can't adjust the crossover frequencies, strike 2. HK subs can't put out enough bass no matter what headunit is there, strike 3.
Start with amp and speakers, and if then you're not satisifed, then you could switch out the headunit and/or add an equalizer...
Better picture coming!