The ones you should really watch out for are 1 ohm loads you must make sure that your amp is 1 ohm stable and in some cases .5 ohms. A lot of what you could be asking can be found in this thread.

http://www.the370z.com/audio-video/6...dio-101-a.html

Ok i am going to use the Ipaul DM2000 amp and here are the specs on it

Power Output at 4 Ohms: 360 Watts RMS
Power Output at 2 Ohms: 730 Watts RMS
Power Output at 1 Ohms: 1000 Watts RMS
THD: <0.02%
S/N Ratio: >95dBA
Frequency Response +/- 3dB: 10Hz-250Hz
Input Sensitivity: 250mV - 6V
Variable Subsonic Filter
Low-pass Filter: 50Hz-250Hz, 24dB/Oct
Current Draw: 90 Amps Maximum
Dimensions: W x H x D:415 x 60 x 250 mm

should i go with a 2,4, or 8 ohm sub
I think the sub i am going to go with is the IDQ12v3.d4 or one of the JL 12W3v3s

You can go with a DVC 4 ohm or a DVC 2 ohm. Either way you can run them. just make sure that you wire the voice coils the right way and also set your gain on the amp.

Should I get the Ipaul DM2000 or is there a JL amp that is better?

Personally I would get a JL HD series amp but that is my preference, others may and will inevitably disagree. I like the HD series becasue they are extremly compact and completely class D for incredible effeciency. For an all class D series amp, they are the best you can get right now. The Alpine PDX is the only other amp out there like them but the JL HD amps are a better amplifer.

The 600/4 would be all that you would need. The 900/5 is overkill but if you want lots of power its the way to go.

I am using the 900/5 and I have 500 watts going to my sub and 100 watts X 2 to mid's and the other 100 watts X 2 going to my tweeters.

Its way more amplifier than I need, I would have sufficed with a 600/4.

The JL amplifiers have much higher damping factor. They are >800 @ 4 ohms and the iPaul is only >160 @ 4 ohms.

The higher the damping factor, the more control the amplifier has over driver which equals tighter, harder hitting bass!

This why higher end, smaller amplifers will outperform larger, less expensive ones. Not all watts are created equal!

I have rainbow cs 265.25 germaniums laying around they sound great i had them in my mazda they are 6.5" let me know if you are interested in them. literally used them for like a week and then i traded the car in lol.

^ LOL needed a faster car man? Ya the rainbows are nice right up there with focal and Image Dynamics.

lol i had a mazda 6 like 3 cars ago. the germs have just been sitting in the box since i havent used them at all. I had a stage 2 vw GLI before the z that i have now.

The germs are nice, most of the rainbows below them in the lineup are mediocre. Just outta curiostiy DAISHI, how much are you looking to sell teh germs for?
Also just an FYI, if you buy rainbow the only way you will get a warranty is at an authorized dealer. No online company is authorized to sell their product.

probably around 300 or so. the price is negotiable. I did get them through an authorized dealer. a got them through a member on caraudio.com he has a shop and is an authorized dealer.

So should I go with a JL HD750/1 amp over the Ipaul DM2000?