I own a couple SET amps of the 2a3 and 300b nature and have them mated to the appropriate speaker. BUT...I also have a more demanding speaker (Magnepan) in another system and I wanted to try a big SET on it. The one I bought and have been happy with for the last 4-5 years is the big Cary 805.
Cary has been making this amp since the mid 90's and there has been several iterations of it. The one I have and would recommend you looking into is the AE (Anniversary Edition), but I would not exclude the others. One of the things I like about the AE is that you can use either the 845 and 211 output tube just by flicking a switch. It's rated at 50 wpc with the 845 and 70 with the 211. I find it very musical. You might consider it.
Cary has been making this amp since the mid 90's and there has been several iterations of it. The one I have and would recommend you looking into is the AE (Anniversary Edition), but I would not exclude the others. One of the things I like about the AE is that you can use either the 845 and 211 output tube just by flicking a switch. It's rated at 50 wpc with the 845 and 70 with the 211. I find it very musical. You might consider it.