The horn shoppe: Aside from bass cut off around 50 Hz, it should have a good tonal balance over all. However, placement and matching amps is tricky.
Loth-X: Have not heard their high end models but entry level ones were quite a disappointment.
Only recommend using 4 Ohm speakers if your SET output transformers are lower than 3K or else you might complain about lack of low frequency response. Keep in mind, most of the commercial version are 5K. The damping factor is very different from speakers to speakers. That's why matching amps is quite important. There is no BS like Beavis mentioned, it is all about science behind speaker and amp design.
Loth-X: Have not heard their high end models but entry level ones were quite a disappointment.
Only recommend using 4 Ohm speakers if your SET output transformers are lower than 3K or else you might complain about lack of low frequency response. Keep in mind, most of the commercial version are 5K. The damping factor is very different from speakers to speakers. That's why matching amps is quite important. There is no BS like Beavis mentioned, it is all about science behind speaker and amp design.