Maybe a Class A solid state amp would get you what you're looking for without losing too much tonality or fluidity. There's a Plinius SA103 and Pass Labs XA100.5s for sale here that might be worth a look. Or maybe a McCormack DNA 500 or a hybrid like a Rogue Medusa, although you might need to change the input tubes to get the right tonal balance as stock tubes may leave you a little cold. Just some ideas, but best of luck.