I have HK AVR-500 for several years and have been very happy with it. However, I change some of my home theater equipment and now need a component switcher. I am thinking just upgrade to Onkyo SR-502 or SR602. 1) What's other receiver should I consider with a limited budget. 2) Do I need 7.1 setup and Dolby EX? Currently I have polk CSI245, R30 up front, R15 rear and a cheap subwooder that will be upgrade soon. Thank You.