Anyhow, I'm in the process of a complete stereo replacement...or get something a little higher so the amp has some headroom? I was looking at a few amps.
Infinity kappa k1000 - 700w at 4ohm
Soundstream t1-4000dl - 700w at 4ohm
I found a factory refurbished kicker cx1200.1 which is 600w at 4ohm.
First, you are sharp trying to pair a sub with the same brand and line: Infinity Kappa K1000.
You'd think no one cares that the better brands are often engineered to work best together.
Thing is, you have a LOT of headroom with the Infinity. It peaks at 2600W 1 ohm. If I am not mistaken, your K1200 sub may have an impedance selector that can be set at either 2 or 4 ohms. So, 1000Watts at a 2 ohm load sounds solid pushing a 1200W peak sub. Thinking about your car. Seems you are driving a pretty small vehicle, with not as much space in the cabin area. If it is a hatchback, and If you are a bass-head, you might want another subwoofer to make things crisp.
Hint: I own a Infinity K1000, it is new. It does not come fused, and requires 4 Gauge amp kit. Get the kit if you need one from CT Sounds on
Amazon. I bought a good one w/ distribution block for $17.
Do your due diligence tuning it, my friend. I would personally steer clear of anything refurbed, and everything by Kicker. Never used Soundstream amps, but I do use their four channel line converter. Not a bad piece of work, albeit made in China since before I was born. Best luck to you.