Friendly suggestion - wait till you have both the mount and press in hand before you start to drill holes and buy hardware. You may need to change your plans if you end up with a support member under one set of mounting screws - will need either long hardware or can use wood lag screws instead. You also want to be sure of positioning of the press before drilling - make sure to have full stroke of the press handle with no interference. Depending on your future plans (case feeders, bullet feeders, etc..) may also need to consider what is above, behind and to the side of the press before settling on a final location. Would also use the beefiest diameter hardware that will work along with fender washers, lock washers and lock-tite. Tighten that sumabitch down. Any movement of the press/mount will be a huge distraction.