Originally Posted by Piotr
I don't exactly get what you are after. You are looking for portability, but search for a two-speaker tube combo with relatively high wattage?
Maybe in comparison with a head plus 4 x 12 cabinet. Closest thing I can think of would be an old Pro Reverb - 40 to 70 watts depending on age, but nearly as loud as a Twin and a little lighter. Neodymium-magnet speakers would reduce the weight further.
Only other way that comes to mind for relative portability would be a custom jobbie like my Peavey Classic 50 chassis in a hand-made solid pine 2 x 10 cabinet. With a pair of Celestion G10S-50s it weighs spot-on 44 lbs and is as loud as you like, clean or overdriven. Doesn't have to be that particular amp chassis for your purposes; it's the principle I'm referring to. Downside is the probable expense involved.