You just want to connect it in your house? Aw man that's EASY! Find yourself any 12v DC addaptor that has a good amount of amps. Strip the wires on the end and test which is positive and negative with a volton meeter. And that's it. Connect it to your amp and you should be good to go. I had no problems with about 1.2A powering a 100watt car amp, never gave me a problem.
One problem you will have is that your soundcard is amplified, so you will get quite loud sound unless your amp has an input designed for this. Most are just preamp. It'll work with the amplified output from your soundcard, it'll just be quite loud and will become distorted very easilly.
OH, another problem you might run into is that remote power. The way I solved this was just set a jumper from the power connection right to the remote power connection.
My old setup was quite cool. I had two amps under my bed(120 and 100 watt) One was connected to two 6" subs with 1" tweeters, the other was connected to an 8" bass tube. When I wanted all that sound, I just flipped on a surge protector under my bed(all this was under/behind my bed, BTW
And the room would be shaking soon enough
I kind of miss that setup...