Depends on your room size and how loud you want to play. I am mating my Amati with VK-75SE with great success, though I don't play super loud and don't mind the compromise in bass weight. I also own Cremona, a little more demanding on power amp than Amati but overall is still excellent.
75SE is the best amp I have heard on Amati, but I admit I haven't heard everything. I don't have the luxury to use 2 75SE due to heat, otherwise I would. VTL or ARC sounds veil in comparison, though they will go lower.
If you don't mind solid state, I will recommend Edge. Heard Amati with Edge G8, almost as good as tube.
75SE is the best amp I have heard on Amati, but I admit I haven't heard everything. I don't have the luxury to use 2 75SE due to heat, otherwise I would. VTL or ARC sounds veil in comparison, though they will go lower.
If you don't mind solid state, I will recommend Edge. Heard Amati with Edge G8, almost as good as tube.