Ok, im re-doing my system, and im adding a 3rd amp, basically im gonna have two 2000 watt mono amps for each sub, now for the components will I be fine with a 2-channel?? Right now i have one set of 3-ways, and one set of 2-ways...

 

Yes, you could use 1 amplifier, but you'd be stuck with no fade control between the front and rear stage, which probably isn't going to yield the results you are hoping for.
Also, keep in mind that you will be altering the impedance by adding more than one set per channel onto the amplifier, thereby altering the output of the amplifier. This isn't a bad thing, but it could push your power output beyond the capabilities of your components, causing damage and/or premature failure of the components if the power is too much for them.
In a normal stereo setup, you want the majority of your output to come from the front stage with the rear simply acting as "fill." Amplifying the front and rear from the same 2-channel amp is going to provide equal power to each set of components which, more than likely, will cause the 2-ways to be louder than the 3-ways simply due to efficiency. If you are using the 3's up front and the 2's out back, your stage would more than likely come out backwards!

 

I just got the NINe.5 for my car (http://www.edesignaudio.com/edv2/pro...roducts_id=550)

Also there is the NINe.4 (http://www.edesignaudio.com/edv2/pro...products_id=46)

Both are highly recommended