Ditch the capacitor always. I have a link on my computer i saved explaining why they are useless if i am ever on it and on the forum ill post it. The kicker comps that others have posted about are my favorite budget sub i have owned about 5 sets of them and never had an issue. As far as the kenwood amp you posted, i didnt open the link but is it the 1000 watt or 1800 watt? I have owned both, the 1000 watt pushing a pair of memphis prs, and the 1800 watt pushing a pair of alpine type rs. Both are great amps! A great setup would be that 1000 watt kenwood amp and 2 of the kicker comps. Then you will have to get your wires. I like kicker wires but its pretty expensive and not completely necessary for that system. Audiopipe make a good kit for cheaper and will handle that sub amp combo no problem.
Also dont buy from crutchfield unless you enjoy paying more for stuff you can find cheaper. There are a few websites i have used that are reliable and have great prices.
Www.sonicelectronix.com
Www.onlinecarstereo.com
Take a look at those two