I lived in Germany for 9 years and also am a great fan of Hefe Weizens.
For a greater mouthfeel you need to add malto dextrine. It's a non-fermentable powder that can be added with the priming sugar at bottling time.
I have seen some recipes call for up to 4 oz, but I think that is WAY too much. One to two ounces should do it.