hey Bill,
I made my own box the other day for my set up, not too hard.
here is the top of the box, its made from hi quality MDF, we sanded down the edges so that it will fit flush where the old cover used to be:
here is the box before we put it in the car, note the lines drawn with pencil to outline where the box sits below. I dont have any better pics of the box itself, but you get the idea. The box isnt all that big either, it doesnt need to be (atleast for a 400 watt RMS dual voice coil 10" Rockford sub):
here is a pic of us testing the box finished in the car, it hasnt yet been carpeted:
hope this helps..
just be cautious about installing the amp, ive had crazy problems with my electrical system the day after i installed it, i think it has to do with where i connected my remote wire to, and possibly where i connected the ground. Also, i think i need to upgrade the battery ground as well, the stock ground is horrible.
red