I've just bought an Ampeg BA210V2 combo. It's the new version that is designed to be tilted back 60 degrees (like a monitor). It's not big but at near 63, toting around even the relatively lightweight 46 pounds can be a chore. I'm thinking of adding casters purely for mobility. Any advice on size and type? As I'll be sitting the amp on its designed tilt when on stage I don't worry about the need to take them on and off - they'll stay on, but I don't want any rattles or anything so big they become obtrusive. I do have a little collapsible dolly as an option. Can I just screw these on or do I need to worry about damaging anything inside the amp? Any advice?