The conversion of tube wattage to solid state wattage is roughly 2 solid state watts equal one tube watt... so a 50 watt tube amp would be roughly as loud as a 100 watt solid state amp.

As for those amps... I would probably not get any of them. Small amps like that are mostly only good for either a nice practice amp... or recording. But its your preference don't let someone on here convince you otherwise.