Tannoy or JBL

JBL. And don't listen to the naysayers. The JBLs respond well to high power. They can handle the power. The Everests max rating is 500 W. Harman uses high power amps in their demos. This is especially if you wanna really give those woofers a workout. It's more about current than watts or voltage, really. I think ideally, you might want to put a lower powered Class A amp on the mid and hf horns and a high powered Class A/B amp on the woofers. I'm looking into this myself for my JBL S4700s.

from Home Theater Review:

The DD66000 has a frequency response of 45Hz - 50kHz (32Hz low-frequency response at -10dB)

worth considering imo

I do have the Tannoy Kensingtons..but with the above choices and the amp, i would jump at the JBLs

JBL specs the bass in an anechoic chamber so their specs are so different than typical high end audio exaggeration.

I have measured flat to 35 hz in a gigantic room of 50,000 square feet!!! A generous sized listening room of 14 x 24 x 10 is 3,360 cubic feet. In a normal/large living room I have seen them go flat to 22 hz. They are very serious in the bottom end. The 67000 goes to 33 hz flat in my giant room.

I've heard the Kingdom Royals in several rooms, I like the Canterbury and Westminsters better.

I would go for good tubes on the Everests if you get those. 100+ watts would control the woofers well. Remember, those are 2 15 inchers per side!

The right lower powered amp would work too, but it is unpredictable which lower powered tube amps will make the woofers go and which won't. Specs don't tell.

Just my 2 cents, but if your thinking of spending this kind of money for this kind of speaker you really should take a look at Classic Audio's T1 or T3. For the price of the JBL you could have the T 1.4 with all field coil drivers (big difference) or the T 3.4 for less. I've heard them several times with Atma-sphere amps and they are spectacular especially with the addition of the field coil drivers. They also make JBL Hartsfield reproductions.
In fact, I believe you could hear them at RMAF this weekend if you wanted to.