According to Richard Vandersteen himself, too much power is much less harmful than too little power. Just use common sense and don't overdrive them. I've been using a 300 watt adcom amp on my vandy 2's for years and they sound wonderful. I would just try all three and pick whichever one sounds the best to you.
What about power for Vandersteen 2 speakers?
I have three amps I can use, 50w YBA, 100w Krell and 200 wpc Rotel. I listen to jazz in a small room and as long as I don't get silly with the volume the smallest amp sounds the best. I know Vandersteen rates the speaker between 40-160w but it works fine with the 50w YBA amp. Is it better to use more power or should I stick with the better sounding YBA?