Hi and welcome to the forum, lots of great folks here and lost of wonderful info - I love this forum and I'm sure you will also.
Anyway, my 2c worth. For the kind of money your talking you have so many wonderful choices you can make. As others have said and I will here, look at some of these makers:
Garbi
Grulla
AyA (No 1)
Arreita
Perhaps a good used Arrizabalaga (The Purdey of Spain)
Any of the well known English makers (this guns are lightweight in a 12, but remember most come with 2 1/2" chambers).
Look around on the various sites. After all looking is most of the fun!!
I would also consider a 16ga (my favorite), but if I had to choose between a 12 or 20, go 12.
Again, welcome and good luck - keep us posted!
All the best!
Greg
