Raven Audio gets good reviews on its tube gear.
Depending upon your budget I'll recommend Line Magnetic 518IA I drive my Deadalus Argos V2s with it. Other Agon members recommend LM's 508IA (in the Tekton DI thread you'll see at least one member using the 508IA with the DIs so you can get direct feedback contacting the persons using the 2 ). The 518 is $4500; the 518IA is $5000
Depending upon your budget I'll recommend Line Magnetic 518IA I drive my Deadalus Argos V2s with it. Other Agon members recommend LM's 508IA (in the Tekton DI thread you'll see at least one member using the 508IA with the DIs so you can get direct feedback contacting the persons using the 2 ). The 518 is $4500; the 518IA is $5000