You want a tweeter with a TINY flange, and you want more than 8 of them... packed together edge-to-edge, as closely as possible.
If you could get a BUNCH of the tweeters that went into the Control 5 monitors... it's a neo-magnet version of the 035Ti, basically. Only about 2" or so in diameter. That'll give close enough center-to-center distance, to achieve acceptable comb-filtering avoidance (comb filtering will only start to occur above about 10KHz, which is generally regarded as "ok").
With one of the older tweeters, you'll wind up with a center-to-center distance between the tweeters, of at least 4 inches. That'll start comb-filtering at 5KHz... which is VERY FREAKING ANNOYING in the near field, IME...
Regards,
Gordon.