You should have your speakers at ear level for the best possible imaging. Your existing sub is perfect for your room. I would try to keep your existing speakers. Is it the size and or the color that your wife isn't happy with?

M80's VP150 QS8's Earthquake SuperNova MKV-15
Integra DTR-7.4 Outlaw 755 Outlaw M200's Outlaw ICBM