Amplifier for Vandersteen 3A sigs?

My brother has the 3A Sigs and he took the traditional, most recommended, route - Audio Research 100.2 SS amp w/ AR LS16 mkII preamp. That combo is guaranteed to deliver satisfying results.

Why not check out the AR 300.2? There's a used one here for ~$3k right now. Teamed with one of AR's tube premaps, I think that would be a serious combination. Even better, one of AR's monster tube amps like the VT-200. for the same price as the 300.2

Quicksilver V-4's and Rogue M-150's are both excellent with the 3A-Sigs.

You might want to look for a pair of the PSE Studio V monoblocks. Very musical.
I have the 3A sigs and started with the PSEs. They are great little amps for a reasonable amount used. Moved up to Theta Dreadnaught to make it easier for home theatre. PSEs used should run around 1k for two monoblocks while a Dreadnaught can run you lots more(depending on the configuration)

I'm 11 years late to this thread but I've used a Krell 300i, Audio Research VT200, Musical Fidelity A308, and most recently a Pass Labs Aleph 3 to drive my 3A Sigs.

The speakers have sounded great with all these amps but the VT200 and Aleph 3 worked the best. In my current setup the Aleph 3 works the best. The speakers are very revealing and musical at the same time.

I've had these speakers for 16 years and continue to be impressed with them.