I have a similar set up with 3a sigs, vcc-1, vsm sig and two 2wq subs. They are pushed by a B&K amp supposedly 200w/ch but probably 175-185 in reality. The room is 15'x20'x8'. I can sustain about 100 dB if I turn the volume to 0. The answer to your question depends upon your room size and your listening habits. Also you don't mention subs which take a lot of the load off your amp. The pioneer claims 140 w/ch but many manufaturers fudge this value some. If you want to add Vandersteen subs later you will need preamp out jacks on the back. I didn't look to see if the Pioneer has that but you should bear it in mind. The Vandersteen subs work more easily with separates. You will have a great set of speakers!
Also, I found that in my room I don't need the center channel when sitting in the sweet spot. The imaging is much better without it. I only use the center when there are more than two people watching. I spoke to Richard Vandersteen once about this and he said that was true but I would hear a difference if I went up to the Vcc-5. I don't know if he was just trying to get me to drop some more cash or if he is right. He does seem to know what he is doing in general. Have you compared the VCC-1 and the VCC-5 A vs. B?
