In a 3-way speaker system, you may want to consider a smaller diameter mid. First, since it will not be playing much bass, the cone area is not as important. However, smaller diameter mids have better off-axis dispersion at higher frequencies. I don't know about fiber/glass wofers (which is the material JBL MS is made of), but woofers made from processed paper are often associated with extended high frequency response. I would recommend to pick up a pair of Hybrid Audio Imagine I51-2. In fact, the set also comes with nice tweeters too (but they don't play well below 5KHz). This set costs $300 new, but you can find lightly used for under $200. I think Focal Polyglass speakers (the 5-1/2 versions) would work well for this application too. Again, they usually cost more than your budget, but you could find good deals locally from dealers or used.