VOLTOR CASV with Noveske 12.5 & Switchblock Question

[marshallwk]

I'm looking at putting together a noveske 12.5 barrel with a switchblock installed from factory together. It's mounted on my upper i'm just looking for handguards now. I want to go with the CASV. Does anyone have any input on whether the extended or midlength is the model to get? I want to run the VOLTOR front sight so the midlength would be prefered. Just wondering if there is enough space to access the switchblock in this length of barrel with the midsize CASV or do I need to get the extended.

And if I need the extended how do I run a front sight if its open at the top to allow access to the switchblock?