That's an interesting question, and a bit complicated to answer. I was checking for pisco tours few days ago and found some "bodegas artesanales", kind of craft or artisan (not sure about the translation) wineries/cellars, in Ica (80km from Pisco), but those are brands I don't know, except El Catador (artisan) and Vista Alegre (more industrial), I think those are good piscos though I have not tasted.

http://www.peruviajesyturismo.com/to...as-de-ica.html
http://www.vistaalegre.com.pe/

I've heard good comments about (artisan) pisco El Catador, from friends. However if you look for reviews in tripadvisor, you'll find good and bad comments about the visit and its pisco (as usual in tripadvisor, I always find good and bad opinions about everything).

When I was in Mendoza, I got some tours, all of them were to artisan or small wineries and found they were not the best argentine wines. I had to call Fabre Montmayou or Nieto Senetiner to visit them by myself (2 of my fave argentine wines). I guess it's similar in Ica.

I do recommend visiting Tacama and Ocucaje by yourself (with a driver, Tacama is near Ica city, 20 minutes from the highway thru a dirt road, it's a beautiful old farm house). Both wineries offer good piscos.
http://www.tacama.com/english/visitenos/index.htm
http://www.ocucaje.com/
Ocucaje is near the higway but more far than Tacama (specially if you depart from Pisco).

You must know that not all piscos are from Pisco town (or even Ica region). At the duty free airport you will a very good pisco called Biondi (always I take Biondis as gifts to my peruvian friends in the US, they are delighted)
http://piscobiondi.com/en/main.html
Biondi is a pisco from Moquegua, a southern region in Peru. And Arequipa produces good piscos too.

Another good pisco I like is produced 80km south of Lima, called Sarcay. Not sure if you can find it in the airport. But a visit to the cellar would imply a full day tour from Lima, not Pisco or Ica.
http://elsarcay.pe/

Viejo Tonel is another good pisco in Ica, you can find it in any market and the airport. Don't know if the cellar receives visits.
http://www.viejotonel.com/index-ingles.html