[kaigoss69]

You can only do so much with $700, and you're going to have to make compromises. You have to decide what your main goals are. My main goals to improve the HiFi system using that budget would be tonality and imaging (sacrificing volume and bass). I would therefore put in an MS-8 and a center channel and call it a day. If I was a "purist", I would put in a 4-channel amp and replace the front door speakers and underseats, nothing else. If I was a bass-head, I would put a box in the trunk with 2 12s and a mono amp. All can be done for $700 or less, but if you want all of the above, then that budget simply won't work.