Looking for some mid priced speakers to bring my HT to life. I currently own some older Marantz SP1515 for the front, but the rear speakers are crap. I need to get a center channel, 2 rears and possibly a sub, although I am not sure about that. For cost purposes I may just rely on my 2 front speakers as they have 15" cones and can handle bass for the time being. I would like to spend about $600-700. I am not partial to any brand, and have not come under the "Bose is best" spell. Thanks for any help!