Orion amps are not bad at all. The thing you have to keep in mind is that even if the amp can put out 1000 watts does not mean you are going to put all that to your sub. When you install your system you have to set all your gains after everything is installed. That means that you will go to your amp and set your gain for your speakers and your sub so when you turn your volume up there is no distortion. So your amp will probably never push all that wattage to your sub. Also another thing is I think 1000 watts in a Z for a sub is a little extreme, but if that is what you want than that is what you can get. Just make sure if you are running 2 subs or one that the ending load will end up to be 2 ohms or if the amp can handle is 1 ohms. Here is a link to how subs can be wired up.
Subwoofer Wiring Diagrams