Why?'s Audio Adventure

[why?]

I'm going to bump my thread back up. I disappeared from the face of the earth for a year, and now I just woke up, with a couple questions.

I bought a wonderful deck, and still need to get it installed. I tried to find people near me to help me, but of course I suck at that.

But anyways, the deck is going to require an amp. To start I just want to run the stock speakers to get use to the deck, but eventually I absolutely want a sub and upgraded speakers of some sort in some place.

I loved D's I6sw in his car, and honestly I am thinking of that type of low power level, but I want something that will be able to hit all the lows unlike the I6SW, which can't get all the way down there. Plus at this point I am not going to use any sound deadening, although that will change if I really get going in this.

Is a 4 + 1 amp really a good buy, or should I get a separate amp for the sub?