I did some selective pruning to some of my dragon fruit trees and now have some cuttings for sale or trade. I have an excellent self fertile variety called Zamorano as described here:

http://www.tropicalfruitnursery.com/dragon/pages/Zamorano.htm

These are up for trade or $5.00 for an 8 -12inch cutting plus shipping. They root very easily.

I believe I also have some extra Physical Grafitti and a couple others.

If you are looking to trade I already have:
Cosmic Charley, Joan M's Magenta, American Beauty, David Bowie, Delight, R. Meyer Red, Purple Haze, Vietnamese Jaina, Namibia Orange, Yellow, Voodoo Child in addition to the already mentioned Zamorano and Physical Grafitti.

Nice collection of dragon fruit! Which variety do you like best and why?

Voodoo child is an excellent tasting variety that most of the time will set fruit on its own which is a quality I really like. I'm still waiting on some of the other varieties to fruit to make a better overall comparison. I'd like to get a hold of some of Edgar Valdivia's varieties.

You may already know this but just as a reference here is are some pitaya synonym names:

1-S = Physical Grafitti
2-S = Cosmic Charlie
3-S =Delight
5-S = Purple Haze
8-S/S8 = Voodoo Child
9-S = Dark Star/Arizona Red
Quang Ong Self Fertile = American Beauty
Ben Poirier Hylocereus polyrhizus = Bloody Mary

Dragon Fruits grow also very well from seeds.

I have saved the seed from a dragon fruit to plant them so now I have 2 of them

from what I understand they do not set flower easily?

No, they do !

It just takes 4-6 years.

compared to citrus it is not long at all ...

Almost all citrus will fruit from seed in 3-5 years if planted in the ground in a warm climate.

some will after 12 years ...
others after 20 years and some even never ...

yes .. and I had the extreme rare luck to get a male lemon even ...