I would strongly second Bignerd's suggestion to seek out older Vintage Khorns rather than the newer ones. They can be had MUCH cheaper, and sound better to my ears in the various systems I've heard each with. As far as SS, don't even go there!!! If you are investing in the Khorns, run them with tubes; you will be MUCH happier with the sound. I've always found the Klipsh horn speakers from the Heritage line to sound rather harsh under SS amplification. If you absolutely must have SS I'd consider something that does not exhibit classic SS traits, but rather strives for more tube-like performance stressing midrange. SS Amps may also be tricky matches with the Khorns. With 104db horn speakers I'd be very careful in my selection of amps, and definitely try to audition, or buy at a price you can easily resell for. SS amps that fall into the category of the type I mention above are mostly lower wattage. The Portal Panache integrated would be the exception at 100wpc, but it has a wonderful midrange and is not at all harsh. Pass Labs Aleph 3 or 30 would be another, but you'd need a pre. You might also check into the Sugden amps, the First Watt amp by Nelson Pass (check on this before buying as that is a very proprietary design and reputedly does not work well with all speakers). Again, I'd really be careful with SS as a mismatch can really ruin your day. On the other hand it would be hard to go wrong with a tube amp. I like the Quicksilver line and would say the Horn Mono's would be a nice candidate. My own personal preference would be in lower powered SET amps (which I use with my LaScalas), or a low-powered push-pull using a pair of direct-heated tubes like 2A3s or 300Bs.
Good luck!
Marco
Good luck!
Marco