So since there so happened to be so many replies I'm just going to reply with one big reply, so look for your name below with the response also there is a general set of more questions below the names. Thanks again for all the help everyone, much appreciated, best response I've gotten on a forum before I think.
Loudz: Alright thanks for the info, I think I might actually be able to afford the ZCON so might jump to it, was doing some of the math and should still be able to get 4-5 cubes per sub with extra batteries and the like. For the price would you agree though ZCON over Sundown X? Also to join into the argument a bit (lol) I had a Sundown X8 on 1K, and honestly I was blown away with what that little thing was able to do, I don't care what some say, they make great subs. I would demo it for friends and what not and they wouldn't believe it was an 8 inch sub, even blew away my buddies dual 12's (albeit they were Kenwood in a sealed box lol).
Jeffdachef: So by what you have said I am assuming you would say go for ZCON's if I can afford them (just got a new job and realized I'm pretty sure I can, along with a Crescendo 5800w amp)?
LosIsATool: Thanks for all the input you've added, I'm actually thinking of grabbing the ZCON's now, honestly they're not much more money and I was going to be running a Crescendo BC5500D anyway, thoughts?
Denim: Seems everyone is saying this, I think I'm goona stick with SSA, just thinking of doing dual 15 inch ZCON's instead now.
General Questions: I actually first off have an alternator question, I'm currently looking at Mechmans alts (if anyone knows anything better let me know) and in doing some research I recently learned that lower output alternators generally output better power at idle than higher output ones, is this true?
I'm currently looking at this page, which is all what Mechman says will fit my Astro,
Alternators - Chevrolet - Astro - 4.3L - 1996 - 2005 - Mechman Alternators
I'm wondering if spending the 700 bucks is worth the 370 amp versus the 350 for the 240 amp, Mechman claims at LEAST 200 amps at idle (more depending on engine idle of course), but I am wondering if say the 370 amp pushes 210 amps at idle, and the 240 pushes 190 amps, what's the point of the doubling in price? Since pretty much all bass demos are done at idle anyway. Oh and something to note, multiple alternators is not an option in this case, did some research on the Astro and in order to do more than 1 alt you gotta remove the AC compressor, which I am not willing to do. So I need an alternator that can keep up with my BC5500D amp, and about 1K watts for the door speakers (actual usage would be lower on the doors, but I'm just saying what the amp output is goona be). I will be using 4 Optima YellowTop deep cycle batteries as well.
Thanks again for the massive amount of help!