Weber makes a ton of different model Mass attenuators. They seem to be made for different wattages. I would be mainly using it for a JTM45 and Orange Rockerverb 50. So I was thinking of the Mass Lite 100w, Mass III 150w or Mass 200? Does it matter which one I get? Are you suppose to get the one that matches as close as possible to the intended wattage? Any down side to just getting the bigger one just in case? Do they all attenuate the same amount and totally the same transparency? Thanks!