Suitcase build help

I found an old suitcase in my attic that I want to build into a boombox.  So far I've been looking at relatively budget components but would love someone to give me feedback on compatibility, or make better recommendations.

-Lepai 2020A amp
-This Celestion neo 5" speaker  
-Dayton Audio ND16FA-6 5/8" Neodymium Dome Tweeter
-These two batteries wired in series or singly if 12v is enough for the amp I end up choosing

The crossover is where I need the most help.  Is there a walkthrough explaining how to build the crossover?  I tried to pick components that sort of match, but I don't know how to make a filter.  I would like the experience of building it myself.  I was thinking of crossing somewhere around 4k.

Well, that's a two pack, and I was under the (possibly misguided) impression that it was better for the amp to run in 24v.  If running at 12v is fine for this amp, I would be much happier with the reduction in weight.  I saw the Monacor SP60 in others' builds, but I can't find it here in the states.  That build is actually one of the inspirations I had in mind when I remembered the suitcase in my attic!

I would estimate it about 20liters.  That is the bag itself, so not counting the ply box and contents.


Edited by crossed - 04 October 2014 at 6:32pm