You do not need the hand guard!  The barrel band doesn't clamp on the hand guard, so there's no problem there.

All krag sights use the same screw hole locations... and since it's a sporter, you can use the rear sight that you prefer and not worry about fitting a handguard.

Bear in mind, a reproduction front sight post is available, however they require the barrel to be dovetailed and brazed.  You're better off using an aftermarket ramp front sight or a 1903 Springfield banded front sight... or if you go with the Kraghaus and Red Dot, just forgo the front sight!