all a 4 ch kit gets you is an extra set of rca's. You can just buy rca's separately if you find a kit you like that only has one set.
The amp has three 25A fuses indicating it needs a little bit more current than a good 8 awg kit can provide so you're going to need a 4 awg kit.
Here's a nice kit for $30. You'd need to pick up a 2nd set of rca's if your head unit has front/rear, or front/rear/sub outputs. If not you'd just need a couple y cables.
http://www.sonicelectronix.com/item_33027_db-Link-XK4ZANL.html