Just getting started. need help

I have recently been bitten by the audio bug since my audiophile dad passed down some seperates to me. I need some help deciding on a pair of full range speakers. I'd like to spend less than a grand on a used pair that I can grow into by upgrading my upstream components. At the moment I have a parasound pre pro, HK 5 channel amp and onkyo dvd/cd player. My speakers are polk towers, sub and surrounds. Thanks for the advice, can't wait to learn from the experts.