Check Amazon.com for pizzele makers...you can read reviews and might see the same brands at the store.
I personally think that the single pizzele maker makes a nicer pizzele...I would think the double one would yeild imperfect pizzele where they would invariably touch.
Don't forget to try and make icecream bowls with your standard recipe...all you have to do is take it off the iron hot and drape over an upside down bowl and allow to cool.