BCM doesn't make a 24'' to the best of my knowledge. They do make a couple 20'' uppers. I'd be willing to bet that it'll shoot 1 MOA just like the Les Baers do as well.
G&R tactical had complete BCM lowers on sale a couple days ago for $360. Of course, with the election they're all gone.
I just picked up another BCM BCG yesterday for $160. Throw in a charging handle for $30-50 (depending on which of their models you want) and that's an excellent rifle for a lot less than the other two.
That said, you won't go wrong either way---they're all excellent choices for what you're going for.