For myself, the best cuts to cure for corned beef or pastrami is the beef plate; which is almost impossible to find; then brisket. Because of the price of brisket in my area, I have tried other cuts of beef, and they all fall short of the flavor and fat content of either the plate or the brisket. So I won't make pastrami unless I can find a brisket, or plate, which I've never been able to get. If you use another beef cut, I would stick with cuts from the chuck.
If you have a whole packer, I would separate the point from the flat, and not any further prior to curing it. You don't have to cure both pieces at the same time. For example, you can freeze the point for later, and just cure the flat. If you can find the right container, a wet brining may not take up much more room than dry curing (dry brining). I prefer dry curing, but I have been able to wet brine (cure) a 7.5 pound flat, in a 2.5 gallon resalable bag.
As a side note; many members will make pastrami out of commercial corned beef. Which is very inexpensive, but it just doesn't taste right to me.