Interesting story..(true)
Your experience with Horizon just cements the reason why I do business with them.
Slow shipping aside (who hasn't had slow shipping from time to time?)
I think they treated you extremely fair, and by replacing the plane showed you tremendous respect.
Very rarely can an accurate post mortem be done on a crash from 400 feet.
At best it is a seat of the pants educated guess. Hardly factual.
And you returned the Saito?
Huge mistake.
Let's see here, you refuse to do business with Horizon.
That leaves Great plains/Tower as the only company you can purchase engines/planes/electronics from.
I suggest you call Great Planes, tell them you just bought a Avistar Select with the radio and engine complete and tell them the same story.
I would be very surprised if they were that generous, but just the same, ask them.
Then when they don't offer to replace the radio and engine you can save yourself the aggravation and cross them off your list.

I hope you take this note in the spirit in which it was written, that is I hope you rethink your position and cool off a wee bit.
As many can attest I too have a short fuse, and have had many a time to regret a thing or two I've said.

Good luck,