barolo and brunello are two different wines. I don't make wine, but I brew beer and am some what of a wine dork. I have been to Montalcino (where Brunellos are made) and it is my understanding that they are made from what the Italians call Sangiovese Grosso. Again, my understanding is that these are the best or first pick of the Sangiovese that they harvest.
As for oaking, most wineries in Montalcino (and all that I have been to in Montalcino) use very large barrels which are used over and over again...very little oak flavor is transmitted to the wine this way. Most of those wineries have been around for hundreds of years and still do things much the same way that they have historically done. They do not use oak like we do here in California. Not sure if this helps.