Best Integrated Tube Amp for 2.5K or Less

...don't you need some juice for these speakers?
you could try pathos hybrid amp that has 80w/ch and its new price is arround 2k.
there is mesa boogie integrated amp that can meet your power requirements. definitely you should go with higher power than nad 340.
in your situation i would go for ss plinius 8200 -- sounds like tubes very musical and worm in fact it's realy my favorite integrated amp that can smoke many separates for the price offered.

Conrad Johnson makes a nice tube integrated amplifier; the CAV-50. You could get a brand new one for $2500.

VTL It-85 is THE only amp in this price range that will be compatible with ESL or planar speakers.

If you remember Fi magazine, they reviewed a system consisting of the Audio Research CA-50 with the ML Aerius i. I own an ARC myself and have very successfully run a pair of ML Aerius with it. My room is 11 x19 x 7. I am not sure if they would have worked as well in a larger room but in my room they sounded great together. I no longer have the ML's but the ARC is driving my Vandersteen 2CE's very well.