There's a ton of people on here who can design and build you a nice box, all they need to know is when you're paying them, what you want, and how big of an area they have to work with //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Both the Fosgate and the Kicker are great amplifiers and put out good power, irregardless as to what people will tell you on here you will not be disappointed either way. There are other brands which may be cheaper that can give you the same result, as well.
The woofers(as stated also) do not "hold" an ohmload. That's the amplifiers job. If an amplifier is 1ohm stable, run that amplifier at 1ohm, no lower of an impedence(until you have more experience and know what you're doing for competitions). Two Dual4 ohm woofers wire to a 4ohm or 1ohm load, in this case a 1ohm load is what you're wanting with that Fosgate. The wiring is easy for this scenario - the positives go together, the negatives go together. Connect them together, then connect them all to the amplifier...easy done.