are there any that could go from 60-120 or 50-150 because i have a 5150 212 and if i buy one and end up trading it for the head, i'd like to still be able to use it
it's good up to the rated power, so a 150W would handle anything below that fine. It's not like they work better matching them up to the rating. The THD Hoplate can handle any amp below 180W, and the Weber Mass 150 will handle anything below 150W. With the Weber however, they tell you to buy a bigger model than your amp is rated at, since the maxed volume setting on a tube amp can exceed the rated power.