@blindjim --
A lot of options with horns/high efficiency speaker approach, many of them quite viable and with different strengths and weaknesses. All-horn or horn hybrid? Subs augmented? Passive or active configuration? Some DIY or not? From a certain perspective, for horns to be horns their best let ’em be big, but more on that later.
Though not small the La Scala’s are actually a fairly compact design for a horn speaker, all-horn at that, and yet they are very fine speakers. Give them a pair of horn subwoofers (likely DIY, sorry), and you’ve got yourself a very capable and versatile package with rather unique traits in the hifi-arena. Alternative all-horn mains could be Volti Audio Vittora’s or Simon Mears Audio Uccello’s.
Or how about speakers from the pro sector (seriously)? A pair of Danley Sound Labs SH50 Synergy horns; as a point source they image like crazy, with dynamics, refinement and coherency to boot. Very good in tight to moderately sized spaces being a point source. Add a pair of DSL TH50 tapped horn subs and you have pure, sonic dynamite in velvet gloves. Oh, yes - I dare you; this will put must high-end offerings costing a gazillion to shame, and yet the total cost here is likely no higher than $20K.
Further from the pro sector; pro cinema speakers, actively configured. Find them used, they’re big and mostly comprises 2 x 15" bass cabs with one or two horns on top. Don’t go and think they’re crude, loud-only speakers (though they’re not beauty queens, to some). Actively driven they’re a sonic delight, and just like the DSL option they’re the speaker equivalent of Daisy Cutters wrapped in satin (it’s not about loudness per se, but rather effortlessness of reproduction; headroom is your friend). Indeed, active config. gives them an edge, and with a pair of horn variant subs as well it’s a rather complete package (it’s what I use myself, actively driven). Why horn subs? Because they’re more refined, enveloping and smooth sounding compared to direct radiating subs. Oh, did I mention this may be the most cost effective solution of 'em all? And yet they easily hold their own.
The latter options hones in on horn/hybrid/high efficiency speakers at their best: being BIG. Older RCA or WE all-horn options, also cinema speakers, are supposedly majestic and the real deal - inquire about them to poster @johnk. However, they take up some serious space and physically simply may not fit into your interiors.
Avantgarde’s to my mind are simply too expensive, sorry to be blunt about this. Above options are cheaper and better, IMHO.