[M4 > loose choke and surefire forend]

You can order direct from Surefire for about $235 delivered.

 

However, I was at Turner's the other day and they had them in stock for $199.

 

I would have bought one there, but I preordered one from Surefire, which I've received. I was a tad miffed that I saw that Turners had one on display before I received mine from Surefire!

 

The Turner's in Orange has a Surefire Foreend for the M4 for $199, but the model # was M73 which is for a Colt M4 carbine.