I searched a bit . I have seen other sites selling it with that product number, but it is not a "actual" Aquila order number. I suspect it is a older code (before 2015) and 50184 and 7U is the same thing, just different coding, but I could be wrong.
Maybe the best thing to do is to contact Mimmo (Aquila's founder) at
http://aquilacorde.com/contacts/?lang=en just to be sure.
They can take some days to answer but are really nice and helping.
Strings are really a personal taste, but I would consider to switch from 7U to Supernylgut 103U (Concert High G).
Here you can find a sample of the difference between New Nylgut and Super Nylgut
https://www.youtube.com/watch?v=VEpBA_McMjg
I find 'em warmer than the New Nylgut, but as I said string is a really personal taste.