Here is my suggetion to you:
-Any HU you want for around $200 (preferably Alpine, Pioneer, or Eclipse)
-1 12" Soundsplinter RL-p ($235)
-Elemental Designs 9.1 ($350 shipped)
Link to sub: http://soundsplinter.com/rlp_premium_series_12_and_15_inch_subwoofer.html If you never heard of...