I take it from what you wrote on the subject line you need everything from the headunit back. Also what type of music will you be listening to most of the time? And what are you looking for? all out bass? sound quality? or a mix?
Honestly, I hate this question. It's far too common and far too vague. We need some details. Namely the following if you would, please: -types of preferred music -Goals. SPL events? daily driving? SQ audiophile? -budget we got already... -the type of vehicle -the rest of your system this will match up with -how much room are you willing to lose to the enclosure -any brands you prefer or want to avoid