Buying today, which one?

Looking at a M4V7 5.56 as a 10.3" pistol or a 11.5" SBR. Besides barrel length and pistol brace is there any difference between these two? I can't find any. I want the extra inch and I'm willing to wait for the the stamp cuz I was going to SBR the pistol anyway. Am I missing anything cuz if not I'm buying the 11.5" today. Store closes in 2 hours your opinion matters.