1 amp or 2, which head unit?

i was wondering which is better when installing you stereo. having one 1000 watt class d amp. or 2 500 watt class d amp. this is for two 2 ohm dvc subs. if any one can help that would be great. also i can't decide which head unit is better. http://www.woofersetc.com/index.cfm?fuseaction=product.display&product_id=4633 or http://www.woofersetc.com/index.cfm?fuseaction=product.display&product_id=4306 i'm not worried about the price i'm looking for sound quality and power. thanks to any one who is goign to help me.

Given that you are considering the same brand (I didn't look at your choices), it is always better to use one amp than two...if impedance allows it, of course.  Sometimes two amps are used in place of one in a situation where you want to put a 2 ohm load onto each amp.  By combining the subs onto one amp, the impedance necessarily has to go one way or the other, and can't stay 2 ohms.  That's just one reason, but in a situation where you haven't purchased the speakers yet, look into using one amp instead of two.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

yea i was looking in to eclipse but the one eclipse that i wanted was discontinued. i was looking at getting the mk7100 i believe is what its called. but i got told that it is no longer available so i went for pioneer. i like them and they have all ways treated me good. but the head units are so close in compairson. just trying to get an idea of which was better. i don't have the amps or the subs picked out yet.

pioneer radios have notoriously poor ground planes and you will get all kinds of noise with them. Especially with amplifiers.