I use owner twistlocks - 4/0 size I believe. There are a lot of options though - you can use a wacky style hook and nose hook it, a regular offset hook and thread it on...just depends what action and how you are going to fish it.
I like to do the donkey rig with two flukes a lot of the time in the summer.
Edit - I would like to add, I rig mine weedless and "upside down", if you will