I've used both.
I use 3068 for hefe's, gives banana character/cloves around 68, might clash with what you actually want. you'll probably end up with something closer to a hefeweizen.
I had diacetyl issues with 3944, but it went away after awhile and I'd say I liked the final product better than with the 3068, especially if you want a belgian wheat.
I love both those yeasts though.