Kenwood amps are.... maybe better than some other budget stuff. They're well known for not doing their rated power. Probably not very efficient. I mean, if it came down to it, I'd still take AP or MB over Kenwood; they at least do rated.
And I'm sure the Kicker box is built to whatever specs Kicker recommends, but whether those specs are any good for a musical enclosure is debatable.
There's plenty of members on here that will build and ship you an enclosure to your door for $200 or less. Also, Skar audio has a deal going on with their subs/enclosures. Single 10" sub + custom built enclosure to your specs, finished and painted how you want, and shipped to your door, for $199. for a 12" it's $209, and for a 15" it's $249. Unbeatable deal there for a great sub and enclosure, especially considering how much it would cost to ship if you had to pay for that. You'll never get a better deal on that if you're looking for a new sub and enclosure, unless it's local; even then it'd probably be used and not as good.