I would prefer to discourage you but it is certainly up to you what to do. My motivations are following:
1) If you wish to explore Milq then you do need over 100dB sensitively but it is not a good idea to build an unknown to you acoustic system of a new for you topology in context of which you would learn what an amp might do.
2) If your new acoustic system be a horn, and if you are new to horns then I would defiantly shell to stay with amplification the you know already and that you feel comfortable with, unless your current amps can’t driver horns.
3) There is no acoustic system requirements know to me that is needed to be used with Milq. You need high sensitively and you need an acoustic system that more or less truthfully handles harmonic content of Sound as Milq has tendency to demonstrate it’s might in context of proper Sound.
4) The idea of single horn speaker is fundamentally contradict, in my view, the concept of horn-loading. There are some people out there who use horns with 6”-15” throat with those horns so-called full-range drivers. You might consult with http://fullrangedriver.com and many others who take this direction. I do like it and I do not call it “true” horns but rather “the drivers with leaves”
Sorry, I am not helpful in your project, but others might provide more “desirable” response.Rgs, Romy the Cat
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche