This has come up a couple of times, the only two kinds of grains I know of that you can use to make a beer like this is sorghum and buckwheat.
I discussed buckwheat with another gentleman in
this thread not all that long ago.
Bodensatz lists malted oats as a possibility for head retention and nutty flavor but says that more than 20% of your grain bill as oats will produce a strong flavor that will not be pleasant.
I would suggest that you look at other adjuncts to improve the body of the sorghum beer. Oatmeal would improve the body on a sorghum base, although it can leave a beer hazy. Mind you, hazy beer is better than no beer.
Gedvondur