I have never had Sushi prepared with brown rice.  Somehow it seems wrong to me.
That certainly sounds non-traditional, but it's probably a little healthier for you.
The lacto-fermentation of the rice prevents fish from spoiling. In one Asian dish, narezushi, salted fish was stored in rice for months at a time.
That's pretty crazy. Is that a popular dish today?
I'm not certain, it was the earliest form of sushi and probably originated with paddy fields along the Mekong river.
That is very interesting. Do you have a favorite kind of sushi?
I pretty much favor the kinds with cooked ingredients these days.
Like tempura? 
No tempura is a different thing altogether.  It is batter made from sparkling water and soft wheat flour
Sorry, I guess I meant tempura shrimp being inside the sushi. Do you have any tips for making sushi at home?