I previously compared the RebelAmp, Lyr 3, and THX AAA 789 in detail. Well, I compared the Rebel and Lyr 3 but quickly realized the 789 is…unpleasant. Mine is in a box on a shelf.
You won’t know if you like tubes until you try them, and one tube amp is not like another tube amp. Each tube varies and the amp can transform with a tube swap, or not change much at all. Some tube amps are effectively identical to solid state amps, while others are heavily distorted in either a good way or a bad way.
I recommend splitting your strategy between a DAC and amps. The BF2 is an easy choice for a $2K budget. That leaves you with $1,300 for amps. You could get the Rebel and Lyr 3 with change left over.