make sure you keep us posted on wahtever you do(or me at least) i'd love to see how things turn out, so far i've built a set of speakers and a sub to match.......
40-18k not too deep, but they sound very clear, i use 'em on my computer, it was pretty cheap to build(i didn't use high quality drivers) but eventually i'll make some more(since it was fun and the outcome was amazing)
good luck!