I have an Alpine PDX 4.150 powering a set of Boston Acoustics SPZ60's in the front and had Boston Acoustics pro60's in the rear. I absolutely love the SPZ60's and they are very happy with the 150 watts rms they're receiving. However, my pro60's recently have blown out. This system sounded spectacular when it was working well, but now I'm looking for some speakers to replace the pro60's to put in the rear. I want to spend under 600 dollars. I could get another set of SPZ's but I want some variety in my system.