To remove a milspec barrel nut it will work great but may or may not work for your new handguard alot of free-floating handguards don't utilize the milspec nut.
i believe i bought mine as part of a combo kit that came with the torque wrench. i also picked up their upper receiver vice block and gas tube alignment tool.
you will need a torque wrench for properly installing any barrel nut, so add that to your shopping list if you dont have one already. the same goes for the vice block. You need some kind of way to lock your upper into the vise that minimizes risk of damage when removing or installing barrel nuts to upper receivers.
don't buy junk, buy one that will last a lifetime. i recommend one of these two. i own the combo wrench it does AR15's and AR10's and these things are built like a tank. buy once cry once as they say. i have built 15 AR15's with mine and 1 AR10 with it so far.