I have narrowed my search on seperates to a B&K Reference 50 Preamp and a B&K av125.7 Amp. I can't afford the Reference 200.7 Will there be that much of a difference between the two amps? I will be using it for home theater 75% and music 25%. Also does anyone have any pros or cons on this equipment. I'm open to suggestions on other gear if you have first hand knowledge on it.