That's a good point about the variety of amps that can drive these things with ease. My LM 518 shouldn't have a problem at all.
@simao I had a 518i a while back and it is indeed a great amp, it wasn't the best pairing with horns. I used it with Forte IIIs and a pair of Khorns. I loved many things about the sound, but it could be a little "strident" at times. Then again, the cornwall IV has a much smoother sounding horn than either of those, so you might be ok. Good luck, interested to know how this combination works out.
As for power, you will be fine. I am driving mine with 16 watts of Aric power and it is plenty.
Oz