I was wondering if responce amps from jaycar are worth getting as i was going to get Response Car Amp 2x80WRMS AA-0420 to power a 10"pioneer in box for my ute so if anyone can post wat they think about them.

No problem will do it nicely. The larger ones aren't much more expensive. I think they were clearing the old series 2 x 150rms which is 500rms bridged. Would be heaps and only $199...