I need some help with my pc audio. I'm currently using the on board sound (Realtek ALC889) with my old Logitech Z680 5.1 system. I also have a Yamaha RX-V765 reciever still sitting in the box. I'm looking at the HT Omega Claro Halo XT card. Can I use this card with the reciever and z680's or do I need to get new speakers too? If that is the case are Polk Audio TL250's worth it or are there good quality, sounding speakers for less?