I can only speak for my purchase of a Line Magnetic LM-805ia: I am not a dealer or a shill. I purchased it from Pitch Perfect Audio in Palm Desert, CA. I forgot the owner's name, but he is a super, stand-up guy and carries a lot of their amps and speakers. I've had it for almost 2 1/2 years with zero issues and the sound (to me) is better than the Prima Luna (tested both amps with the same Tannoy Turnberry speakers). If you go with one, I'd suggest swapping in some NOS Melz 6SN7's, a National Union 1940's NOS 6SL7, PSVANCE ACME 805, and PSVANE ACME 300b tubes. I estimate a 20-25% sound improvement over the original tubes. My homemade power cord out of Dueland 600v wires and parts connexion plugs made a nice improvement in sound as did my homemade Dueland RCA cables with the Dueland RCA's. Yes, it's possible: you can buy a China amplifier and still have a place to go back to/contact if you experience any issues. From what I remember the main Line Magnetic service/repair/warranty facility is in Arizona.
If you find an all-American-made amp that can compete with this one's sound, quality, and price please let me know.