Go to cash & carry they sell all the primal cut / packer meats that's were I go.
burnt ends is just that.....any part of the outer bark, thinner areas may burn faster than others but anything burnt to your liking is burnt ends. There is only so much yield from one brisket. BBQ shacks have burnt ends on hand because the cook a bunch of brisket on a continuous basis.

A packer is a whole untrimmed all fat included brisket weighing from #10-#15+ lbs.
any large chunk of meat is also called a primal cut commercially.
For example a whole prime rib roast before being cut into rib steaks.
A packer lets you decide how much to trim and from were to trim.
Fat equals "flavor" and overall "tenderness" during the cooking process.
The point is the thicker end usually with the most fat left on by the butcher when buying a trimmed brisket. The flat is just that....the flatter part with usually more fat trimmed off most often the 1/2 with little to no fat top or bottom.
A packer will have alot of fat sometimes a layer of fat then a thinner layer of meat then another layer of fat then the main meat layer of the brisket. I separate the layers and get a small thin kind of brisket from the top then trim the fat on the main to the way I like it.
You should expect to lose about 25% - 33% of weight in the cooking process.
Give yourself a good 16-24 hrs of time for a slow roll on a 10 to 15+ pounder

You need to figure 1 1/2 hrs per pound at 225 dgr. put it in the smoker and leave it do not keep opening it to look at it!!!! Every time you open the smoker and lose heat you will be adding 15-20 mins to the cook time so don't keep peeking be patient.
When the internal temp is at 180 its done but the amount of time per pound is the key to tender melt in your mouth brisket. Make sure to put your rub on the night before and wrap it tight in saran wrap.
when you take it out of the smoker wrap it tight in foil then wrap in a towel and put it in a cooler for 1/2 to 1 hour before slicing. This give the meat time to rest and distribute the juices thus adding to the succulence.
Here is a couple about 5 hrs in.....The main larger on is on the left with the point to the left and the flat to the right. The small pieces are from between the layers I mentioned when trimming a packer that some times have a little meat between fat layer on top of the main brisket.
Enjoy and let us know how it turns out