jglad,
That center channel speaker is not going to keep up with the mains period. I know as I have the KV-2 as well. It sits in my living room with my cheesy setup consisting of retired HT A/V gear. In the dedicated home theater room, it was replaced 7 or 8 years ago with a Klipsch KT-LCR. As soon as I replaced that whimpy center, my HT came to life. In my opinion, the single KV-2 is not going to cut it with the rest of your equipment. Sure, you can get an amp that will push it to the same dB levels as the mains, but it is going to sound harsh and very thin when it gets there. My suggestions:
1) Try to find a KT-LCR (these THX certifed 31 lb center channels are awesome)
2) Get another KV-2 and split the signal to both of them increasing the volume by 3 dB (I would go with #1)