I certainly wouldn't put myself in a position of having no financial safety net to drive an Impreza worth £2500... to be honest, as it sounds like you're after a car to smoke around in that's got a decent turn of speed then I'd 100% be looking for a V70 T5 which will tick a lot of boxes and shouldn't lose much/if any value as long as its kept straight and clean.
Cheers,
Grant