NM, sorry, brain fart, forgot there were actually soundbars that require external amplification. What one do you have now? How about painting it white?
HDMI CEC may offer the turn on/off thing easily enough, tho. As to voice enhancement, you may just need a better center channel speaker but an avr would let you boost the level of the center channel.
Not into the aesthetics, particularly if colored white, much prefer black myself so have no idea what's available in white....