A witbeir is different from a german weizen in several different ways. First, the witbeir does have a bit of unmalted wheat. It adds more haziness and a different flavor than malted wheat does. Also, it is fermented with different yeasts. The weizen use german wheat beer yeast and the witbeir uses a belgian wit yeast. Both are ales.
Also, a witbier tends to have spices added to it, such as coriander, chamomile, citrus zest. If you do a search in the recipe forums, you can find a lot of good Wit's. If not, send me a PM, I have a great witbeir recipe that won 3rd place in a local comp.