Dude there is no need to worry about overloading your electrical system. Your 7th gen has a plenty big alt 70 or 80amps. Running two amps vs one amp with the same amount of watts is exactly the same. Until you get over 1200w or so your absolutely fine, I really don't want you to worry about that. Now if this was a 1989 accord yeah that may be an issue, but that is not the case.

Running a low powered sub with it's rated power will sound better, it will be crisper and have better response. A larger sub running off less power may be louder, but will sound a bit muddy. But there is no reason you can't supply your sub with 500w.

This is what you should do, keep running that kicker amp for your speakers, and get a 500w or even 750w amp for a sub. You will have a very nice sounding sub in that power range. This will not impose any kind of load on your electrical system, it will handle it just fine with the small battery. The smaller battery just won't let you play music for very long with the car off. With the car on and with such a small system your alternator is what's really going to be feeding your amps.

Also I see your looking at the type-r, while it is a nice SQ sub it does lack in the SPL department. Personally I like a lot of bass, but still have nice SQ. A CVX is my favorite sub in that price range. It can get VERY loud, and still keep the quality up. My all time favorite subs are the W6 and W7, even though they are not SPL monsters they are just sex.

EDIT: I see you have a 6th and not a 7th gen. I don't know the alt size in the 6g, but it is still plenty big. Remember these amps don't ever draw their max RMS constantly, even when blasting. They do get close when you really crank it up, but still VERY safe with your car. I'm surprised your in high school, I was thinking your an older guy used to really old cars with a itty bitty alternators, now a days that is not at all the case.

 

Yeah im still in high school but my dad is always on my back about me throwing out the alternator so i guess thats why im so cautious with this stuff. I will be on the lookout for a mono amp at my local shops. Thanks for all the info!