You could look for a pair of B&W 685s used. Likely would cost ~$350 shipped ($650 when new). They are front ported and work well close to back wall. One issue is that they require power much as the aforementioned Dali and Elacs do. Many think very highly of the Silverline Minuets, as recommended by uncledemp. They are easier to drive and sealed box but harder to find used (I have been watching for a used pair myself).
My concern is that the FX-10 amplifier will severely limit your choice of speakers that fit your budget. Unless you have a large listening room or like to make your ears bleed, I believe a quality SS 50wpc amplifier, one that can play into 4 ohms, can mate well power wise with most budget speakers having 86-90 dB sensitivity and nominal impedance of 6-8 ohms (allowing of a dip ~4 ohms somewhere in frequency range). I use an NAD 326BEE (50wpc) and have driven several such speakers, including the 685s in a second system.
One last thought, I seems that you are in need of speakers and an integrated amplifier. This becomes a difficult proposition with a budget of $500 and the current list of recommended speakers. You might consider looking for a used integrated amp and purchase a pair of Pioneer BS21s, 22s or 41s which can be found for ~$100. These are a very highly recommended truly budget speaker. This will allow you to enjoy your music now, purchase an integrated amp that will drive an upgraded speaker in the future, and to develop a feel for what attributes you most desire from a speaker while exploring the speaker market at your leisure.
Good luck in your quest!
My concern is that the FX-10 amplifier will severely limit your choice of speakers that fit your budget. Unless you have a large listening room or like to make your ears bleed, I believe a quality SS 50wpc amplifier, one that can play into 4 ohms, can mate well power wise with most budget speakers having 86-90 dB sensitivity and nominal impedance of 6-8 ohms (allowing of a dip ~4 ohms somewhere in frequency range). I use an NAD 326BEE (50wpc) and have driven several such speakers, including the 685s in a second system.
One last thought, I seems that you are in need of speakers and an integrated amplifier. This becomes a difficult proposition with a budget of $500 and the current list of recommended speakers. You might consider looking for a used integrated amp and purchase a pair of Pioneer BS21s, 22s or 41s which can be found for ~$100. These are a very highly recommended truly budget speaker. This will allow you to enjoy your music now, purchase an integrated amp that will drive an upgraded speaker in the future, and to develop a feel for what attributes you most desire from a speaker while exploring the speaker market at your leisure.
Good luck in your quest!