I don't really know any Thorens amps, I'm familiar with their turntables (which are excellent), but I couldn't give you anymore information about the monoblocks.

The luxman: Luxman is a great brand, and has a great sound. Some of their vintage amps go for really high prices, and much of their gear is pretty valuable. However, I don't really find much about the M-1600. This does not nessecarily indicate that it's a bad amp, but it probably didn't really stand out either.
I really like the luxman sound though...

Are these your only 2 options??

Keep them spinning,
Bert.