I like Definitive Technology too. I forgot about them for some reason. I have not heard their bookshelf speakers, but I imagine they are pretty good. They do have the non-powered towers which could save you quite a bit of money. Many, if not all (towers anyway, haven't looked at anything but big surround systems from them), Def Techs are 4-8 ohms, so you would be getting 300 Watts from the amp into a speaker around 91 db sensitivity.