The DMS I posted are what everyone raves about in the rally cross circle. You're not going to find a lot of tarmac coilovers that will take what you want to throw at them very well, especially not budget models on the low of your budget that don't even handle street driving very well.
I would ask what people recommend on Dirty Impreza. I know they usually give strut recommendations rather than coilover ones. Any reason you want coilovers over struts? Lowering a car generally doesn't go hand in hand with what you're wanting to do, and every time you change ride height you're gonna need to get an alignment, so it's not like you can go back and forth on a whim.