newbie need help on decision on buying an amp

While I have never owned the 3's, I have owned 2 pairs of the model 2 speakers.
I did once drive them with a 30 watt tube amp, but this was in a small (12x15) room. When I moved them into a 12x26 room, the amp did not have enough power. Bass and highs were rolled off and when I push the amp too hard, the sound would distort and soundstage would collapse.
That said, the 3's need more power than the 2's. If you want tubes and they sound good with tubes, I suggest a pair of the Quicksilver Silver 90 monoblocks. You will have to hunt or wait for these to come up for sale, but you will see them from time to time.

I agree with Philefreak. Manufacturers recommendations are a good start.

i used a small 20-30 watt amp with a pair of Vandersteen 1-b's and it sounded pretty good at low volumes. Then one day i had it cranked...sounded great. Then the amp clipped and it sounded expensive. get a bigger amp

Also agree with Todd Philefreak: low power amps have caused an awful lot of blown tweeters - while going the other way (more than rated power) rarely results in problems when applied judiciously.

The obvious amp/preamp choice would be Audio Research, it is the most used combination with Vandersteen's and what Richard V. himself used to use at a lot of trade shows.

My brother has the 3A Sigs and drives them with the solid state AR 100.2 and tubed LS-16 preamp. I spent a month staying at his house while he was on his honeymoon and found the 100.2 to have plenty of power(100 wpc) and a firm grasp of the 3A's woofers, athough I personally felt that the LS-16 gave music a "woolly" and unfocused feel. But, that is an entirely personal opinion and my brother also has his system in far too small of a room(~10'x12') for critical listening. It's no wonder things sounded a liitle muddied.

Anyway, definetly audition ARC with your Vandies.