Good man Aldukes, very hard to wrong with Prum Auslese. If you're only buying one of each, you better have a lot patiance as these are going to start getting good in like 15years or so. Id think about getting 2of the same so at least you can try one in 5-8 years and know what youve got. These may be very sulfury if you open one now.
That being said, these are cream of the crop. I have had tons of Wehlener Sonnenuhr and it always pretty great. Top vineyard and big dog in the Mosel. I have not had too many Zeltingers and it seems harder to find Prums version. Theoretical could be a little riper and less mineraly but thats a guess. The vineyards are basicaly adjacent (as is Wehelen and Zeltingen)
PS: Sonnenuhr means "sundial" and there is a big clock about halfway down the vineyard slope.
~Vitis