you want some space in your trunk? id try getting your hands on a stereo integrity 12" bm v4. the box i believe is 0.5 ft^3 sealed and output is great as well as the sq. as for the amp...sundown make a good 2 channel amp that would match well. sax-125. something like that. as for wiring. check out knukonceptz.com they have amp kits that are great and SUPER cheap (also test on the alum-oxide have been done and show little to no difference with pure copper). and yes 1/0 is over kill for you. you need a 4 gauge run. just fyi, you'd benefit from amping your front stage.
good luck with the build.
you can build a great system, for more than 1/2 off of mainstream brands...plus you'd get awesome customer service from the smaller companies.