By body, do you mean more backbone/resistance when you face-lathering?
If so, then all you really need to do is have the knot set at a lower loft.
Any of the brush artisans can do this with a badger knot of your choice, or you can even do it. Just buy a handle and a stand-alone knot, then set it to your desired loft.
For example, if you use a 24mm diameter knot, you could set it at 44-48mm depending on how much backbone/body you prefer.
Also, be aware that most 2-Band knots will be firmer than 3-Band ones.
Good luck.
Looking for more body