Stand Alone Super Tweeter for Revel F208?

AMTs are in general, the opposite of what I would recommend for the OP. 

You can buy Mundorf bipolar AMT's at Madisound. Excellent performners, but you'll need to make a little stand. Not much more than a block of wood with a slot cut across it for the tweeter's lower lip. 

HOWEVER, they simply do not sound like what the OP is asking for. 

They are glass smooth. Supremely natural. 

Golden Ear Triton one's achieve this by a severe boost around 10 kHz. If that's the sound you want, you need to sculpt the HF response. 

https://www.stereophile.com/content/goldenear-technology-triton-one-loudspeaker-measurements

<< shiver >> god those speakers are ear drills to me.... but for many this may make up for lost hearing there, so the combination of spaeker + owner may be ideal. 

Golden Ear Triton one’s achieve this by a severe boost around 10 kHz. If that’s the sound you want, you need to sculpt the HF response.

https://www.stereophile.com/content/goldenear-technology-triton-one-loudspeaker-measurements

<< shiver >> god those speakers are ear drills to me.... but for many this may make up for lost hearing there, so the combination of spaeker + owner may be ideal.

"Ear drill" is the perfect description. I’ve always suspected they were designed for older listeners (the guys who tend to have money) with hearing loss.

Update- I bought a pair of Taket Batpure super tweeters. I wasn't even sure if they were working. I would try with and without and it seemed sometimes I could tell a difference and other times not. I have had them connected now for a couple of weeks and decided to disconnect them last night. Everything seemed flat and lifeless without them. If you connect these things by themselves you can't even hear them!

I have read through this thread,  overall, I agree with Erik.  I would do a tow in with these speakers and get a better handle of what you are after... A bit more tilt up of the treble region? 
Better air  & detail around the instruments?
More energy in the treble region.  
You can achieve some improvement in air & detail or maybe a bit more energy in the high frequencies with a simple switchout of a few capacitors with the same value. 

@honashagen -- congratulations, the result you have achieved is exactly what I would have expected -- do you also find that the quality of the bass has improved, with more crispness and tightness to notes? Anyway having lived with STs for over a year now every time I would no be going back