Good tube amps to consider wit Spendor S5e

My system consists of Vishnu power cord, Benchmark DAC1, VTL 2.5 Pre, Bryston 3B ST Amp and Spendor S5e speakers. I would like to explore the benefits of upgrading to a tube amp.

I have looked into the Unison Research P30K, but have some reservations about it's compatability with the Spendors. I read that for Single Ended Triode amps I should stick to 93+ dB/1W/1m sensitivity and impedance of 8+ ohms nominal and no dips below 6 ohms minimum.

My Spendors are at 87 dB nominal, 8 ohms nominal and 4.4 ohms minimum.

Are there SET amps that would match well with my Spendors in the $2-3K price range.