Which one to choose between two 80K$ tube amps?

What particular vintage WE horn system are you looking at?  Are you looking for a complete vintage system, or are you looking to build a system from vintage drivers and horns?  I have heard many systems built from vintage drivers and horns and these can be very nice. 

But, as far as sound quality goes, there is no reason to avoid considering replicas made by G.I.P. Laboratories; they make terrific replicas of Western Electric field coil drivers.  These replicas cost about as much as genuine vintage drivers.  They make a few updated and improved versions of certain Western Electric drivers, but, these are exorbitantly priced.  I have heard the upgraded version of the 597 tweeter and it is very good (the upgraded tweeter sells for $58,000 for a pair).

I have a sort of modern system, based on old school design.  It uses twin 12" woofers with alnico magnets, and pleated paper surrounds in a Onken bass reflex cabinet.  The midrange compression driver is a Western Electric 713b (my favorite driver) feeding a Western Electric KS 120125 horn.  The tweeter is a Fostex bullet-type tweeter.  I am having a crossover designed around Western Electric paper in oil capacitors built for me.  I will probably also upgrade the wiring of the speaker (Audio Note silver wire).

What Western Electric system did you hear?  With the exception of the Western Electric 753 and 757, they did not make many complete systems.  It was more the case of someone assembling a system from components.  Do you recall what components or system you heard?

The same can be said of G.I.P. drivers, they have to be assembled by someone into a system. How someone did this makes all the difference and you cannot judge the drivers as good or bad based on any one particular assembly.  G.I.P. does make very expensive systems, utilizing their own cabinets and drivers; I have not heard any such system and I don't know what they sound like.

shkong,

Unfotunately, the link to your photos is not working.  But, in any case, if you found something specific that you heard and liked, it does not matter what anyone else thinks.  Whether you get it or another vintage Western-based system, you can be well assured that you can always get your money back if you later decide to sell it; Western Electric prices go up and almost never down.

In the price/quality range you are looking at, it is hard to think of many high efficiency systems that I would recommend, although you could be in the market for custom designs.  It appears that you have already auditioned a number of good candidates, like the JBL system and Avantgarde speakers.  

Good luck on your search.  You certainly have the good fortune of being able to enjoy the Lansche system while search for something else.