If you mean the extremely thick fans in the GFB series
http://www.sidewindercomputers.com/de12gf.html those are only for select uses. Since they are so large they can push more CFM (the critical part of cooling) at a lower DB rating. They are mostly for open cases and suicide runs.
You can always buy a fan controler and use that, deltas normally don't ship with either a molex or a 3 pin. They assume if you're buying that grade of fan you have the ability to do the soldering/electrical work yourself. However that site will solder the connectors for you which is why I recommened them.
If noise is no issue for you (or if you have a controler) I would go with either of these.
http://www.sidewindercomputers.com/delffb1212eh.html
This pushes a simply insane amount of air. However it does sound like a dustbuster at full blast. And it can and will blow out a normal 3pin connector. It's a monster.
http://www.sidewindercomputers.com/de12trblhisp.html
While this moves less CFM it's more directional. For example if you put it on a heat sink it will blast all the air dead at the center isntead of all over the place. It's not as loud either due to the tri blade design.
If you want to just say "to hell with it" this monster is what you want
http://www.sidewindercomputers.com/de12tfexhisp.html put as an exhaust fan it can create a vacume in the PC. 220 CFM is outright insane.