ex3 slow motion
 

what would be the ideal setup for the ex3, and vegas 9, to get the slooooowest possible slow mo shot? I will be shooting a commercial, and part of it is going to include a kid rocking out with his guitar in his room, I want a really slow shot (but still crisp) of him wailing away.

obviously the S&Q mode, so 720p/24p at 60fps, but should I crank the shutter up? and is there anything else I can do in vegas to make it slower, yet still look smooth? or am I limited to the playback rate and the velocity band?