Depends on a couple things. The size of your scopes bell or front of scope and how high the mounts need to be for adequate clearance. Another is personal preference and where your eye is located when making comfortable, repeatable contact with your bows cheek piece.
Boo, a member here on CBN, would be a great resource for you.
The problem with using low rings is you could run out of elevation adjustment in the turret before you get it sighted in. Excalibur uses medium height rings also I am almost positive Excalibur uses 30 mm Rings on the Tact Zone and Twilight scope and 1" on the rest. I'm not sure about the Tact 100 but i think it's also 30 mm.